Explain the ways in which the term redemption and the phrase “salvation lies within” are meaningful to this film?

When one goes to prison, the purpose is supposedly one of rebirth, to move in a kind of monastic isolation from the world, in order to think of the crimes (sins) that you have committed, and to return to society renewed. Andy makes this point when he says that he went into prison “naked as the day you were born”, and when he escapes, he does so with new clothes, and clean shoes. Shawshank Redemption then becomes a tale of what occurred between these places, and sometimes what happened was death, or rape, or destruction, and sometimes it was a kind of miraculous redeeming, a redeeming that was mostly not done by the warden or the guards, but by the people themselves.
In fact, the idea of salvation lying within has multiple meanings, Being inside, is sometimes an extension of the Socratic idea of knowing oneself, but it can be also being inside, being in the prison itself. Andy, after being raped, and almost killed, after having his property destroyed, and having been incredibly lonely, argues this “Forget that... there are places in this world that aren't made out of stone. That there's something inside... that they can't get to, that they can't touch. That's yours.” 1What they cannot touch is protected and extended by the prison so much, that when people are released, or redeemed in the more traditional view of the word, genuine trauma occurs.
The librarian Brooks Hatlen, who has his own power, his own routines, his own rituals, and even his own pet in the prison, and who has been there for 40 or more years when he is released, is killed by the strangeness of the outside world. He is unable to redeem himself. Andy is capable of redeeming himself from the Prison, not because of the Warden or parole boards good graces, but because he had an interior life and was able to keep himself from being bored in prison. He had projects, and hope to get out. There is an intertwining, refusing to be redeemed by the prison or the state, and refusing the states obsessive power over you, means that extending yourself past the prisons and provides a way for the soul to be free. (So he carves the chess set, he does other people's taxes, he writes two letters a week to get a library, he teaches a kid to have a GED, and he plans an immaculate escape)---because working his mind externally, allows for the corporeal self to be trained for whatever the world will bring. There is no need to do good works, the prison is inside, but the mind can be made to work outside the prison, outside the self. Salvation then becomes a modified form of the works gospel, where the desire to escape (i.e. salvation) can only occur internally.
(A good example of this is all in Red's character, he goes through 30 years of parole hearings, begging that he is redeemed, that he is willing and ready to go outside. When the kid that Andy is tutoring is murdered by the corrupt warden, and Andy has escaped, he finally stops playing the games expected of him, he becomes himself and tells the world what he thinks: “There's not a day goes by I don't feel regret. Not because I'm in here, or because you think I should. I look back on the way I was then: a young, stupid kid who committed that terrible crime. I want to talk to him. I want to try and talk some sense to him, tell him the way things are. But I can't. That kid's long gone and this old man is all that's left. I got to live with that. Rehabilitated? It's just a bullshit word. So you go on and stamp your form, sonny, and stop wasting my time. Because to tell you the truth, I don't give a shit. “
To be saved from within is then not giving a shit about the institutions that are keeping you inside, a paradoxical desire for chaos, because when one is so controlled then the self is sapped and lost.

How is Andy A Christ-figure? What does this say to a contemporary North American audience?

Andy suffers. He is set upon by his enemies. He collects a group of people, who are willing to follow him, to listen to his wise counsel. The hole could be considered like descending into the underworld for three days, he is merciful to those who hate him, he is quiet, meek, modest, and patient, slow to anger, but when he is angry, he destroys his enemies. Red's speaks of him like he is John the Baptist, in the wilderness waiting for the messiah to come, and at least one of his followers, tells Andy the truth, and this truth telling results in an explicit martyrdom, engaged at least partially by the state.
The problems or the gaps of this reading do a nice job of explaining the problems with this film. The enemies that he is set upon are homosexuals, so there is a nasty, almost homophobic component to the idea—namely, that Andy is this sainted innocent, whose life is destroyed by murderous queer men, who sublimate his power with sexual violence. Though prison rape is a very real issue, the mythology of the film, and the clear moral boundaries between the villains and heroes suggests that there is a larger attempt towards mythological truth telling then verisimilitudous realism.
This allegorical extension is furthered in the second problem. Andy, with the possible exception of Red is amoral. He cheats, lies, steals, and helps people who are genuinely evil do the same thing. Though he sets up a library to apparently help, it is done for his own vainglory. The library lets him have power and control. It lets him be the same kind of mover or entrepreneur that Red is on a much larger scale, and it allows him to have a project, to not be bored as he is spends decades on his escape plan. This is placed in stark relief at the end, when he escapes to Mexico, with the evil warden's money.
He does not die for the other prisoners, and any help he has to make their lives liveable, to make their lives better is mostly for his own aggrandizement. His co-opting of the Morgan Freeman character, for his resourcefulness and skill, suggest that he does not really spend much time thinking about anything but his own power. He becomes the church mouse mirror of Pretty Boy Floyd or Bonnie and Clyde. Except, it's all so very clean and precise. There is a man who thinks that he is smarter then anyone else, who commits acts of major finical malfeasance in order to only free himself, and if his co worker happened to get out in time, then Red as well.
The audience is allowed any number of outs. Andy is really innocent, so the escape has no real moral problems. The warden is so evil that there are no problems with screwing him over. His friend was let out of jail legitimately by the state, and so, as a criminal (and the only explicit black character) is no longer one thanks to the great skills of this magical white man. They live for the rest of their lives as two straight guys in a vague tropical resort. That's pretty much the current North American character right there—violent homophobia, a suspicion of the state, casual racism, innocent working class white men, venal and evil rulers, and the odd piece of white collar crime forgiven because the person doing it is more moral then the person they are victimizing.

How would you characterise the way in which the Bible is used and how the religious are portrayed in this film?

The first thing that the prisoners hear from the warden, after they are stripped and made anew is that “I believe in two things, discipline and the bible. Trust in the Lord but your ass belongs to me” The first thing that the prisoners receive are a bible and a set of clothes. When Andy's room is tossed, the warden and Andy trade bible verses, adding to this idea that the gospels are to be used as a tool in the extended power games throughout the film. When the library is built, there is emphatically an absence of a religious texts. When the kid who is killed by the Warden, they quote scripture, and when Andy leaves the day of his escape, the bible and the accounting books are interchangeable. Not only interchangeable, but the bible contains the rockhammer which Andy used to escape.
In this reading, the Warden uses the scripture to maintain his power and to hide the copious sins that he is committing. The bible becomes an extension of the state---Lewis' warning against American fascism is embodied in one man. Andy's use of the bible, as a tool of liberation as a way to hide contraband, as a way of finding salvation from within, and as one text among many that give people a generally forward direction. The use of the scripture then becomes an allegorical device that extends this protestant idea that splits those who believe into those who are legalistic, who are followers of the words and not the actions, versus those who are pluralistic, and whose words are an impetuous towards some kind of action.

What is the film's message about the relationship among the human spirit and hope and despair?
Hope is about work. Hope is about knowing oneself. Hope is about realizing one has the power to do small actions over and over again until the task is completed. Hope is lost when comfort is gone, and there is something comforting in the everyday, in knowing when one is fed or allowed to exercise or any of that work. When one gives up hope, one often dies. (like Brooks the librarian, who kills himself because he gave up hope after failing to integrate; or the kid who is killed by the Warden, because he had hope about Andy being proven innocent and worked to get him out.)
Hope is not a good thing in this film. For a film that is supposed to be about the triumph of the human spirit, the desire to be reminded as Andy said, “that there are places in this world that are not made out of stone” is not something that provides comfort. Red responds to that idea “Let me tell you something my friend. Hope is a dangerous thing. Hope can drive a man insane. “
Andy wins the rhetorical argument in the end, when Red is out and travelling with him to Mexico, to live the rest of their lives. But Andy is right, and it is something that the film sort of avoids. Andy embodies the Dickinson idea that
“Hope is the thing with feathers
That perches in the soul,
And sings the tune without the words,
And never stops at all,

But the only thing with feathers in the entire film is Brooks bird, who is released when he is. But the bird flies away, and Brooks never manages it. Prison is difficult. Though the film alludes every so often, to the idea of how dehumanizing this could be, and though the film has a fair amount of violence, the conclusions suggest that hoping will allow you to fly, allow you to be released or to escape and live forever in this paradisical fantasia.
What about the kid, with a family and young children who was killed. He had hope, sometimes quashed, but hope that Andy as an innocent would be released, and that he would be able to return to civilization. He was shot by a corrupt warden. Or what about Red, who was only released, who was only allowed to retain his role in civilization after he admitted he was with out hope. Or even Brooks himself, Brooks crow flew away, but his hope sat on the chest like a weight so heavy he had to kill himself to release it. The film hints but never says something. Hope is a difficult thing, it will curtail you in delusion, it will disappoint you or discipline you as often as it will provide you with something to work towards or look forward to.
Hope and despair are not opposites, one does not despair due to a lack of hope, but hope and despair work together, endlessly feeding off of each other. Red says at the end of the film, just before he sees Andy: “I find I'm so excited, I can barely sit still or hold a thought in my head. I think it's the excitement only a free man can feel, a free man at the start of a long journey whose conclusion is uncertain. I hope I can make it across the border. I hope to see my friend, and shake his hand. I hope the Pacific is as blue as it has been in my dreams. I hope. “ So that by giving up (what could be determined, perhaps) to be false hope, the hope of the structure of the prison, he is released into the wide world, and he finds something resembling true hope—and this true hope ends with some kind of happiness.
It is a hygienic end to an oversimplified story. It forgets Brooks, it forgets the kid being shot, it suggests that corruption is defeated when one bad apple is found and destroyed. It does not talk about the racism that would occur when a black man buys a bus ticket from Maine to Texas. There is this naïve idea throughout that hope makes all borders pliable, be them between human beings or between nations. In the real world, in the south, in the 1960s, there would be encounters with sheriffs, and with border control guards, and the giving up on hope would result in more despair, not something more true and more pure.

How does the message of the plaque relate the film.

Assuming that the plaque means the one that names the library as the Brooks Memorial Library, the plaque relates to the themes of escape, and to returning to the prison, of being inside, and making a site of great psychic destruction into something more normal. The prison killed Brooks, and to place a plaque memorialising this is a logical and culturally appropriate way of marking the site, of confirming the psycho-geographic heritage of death in that place, and also by extension, allowing everyone there to realise that the work being done inside the library walls was work that continued with the traditions that Brooks had been constructing for decades.
That the library would be the front for white collar crime, slave labour, and eventually conspiracy to commit murder, the spirit of Brooks would be aware that the library could not be kept pure, though he was a contraband mule throughout the prison, the library was sanctuary against that kind of behaviour, so the message might also be about the nature of corruption, about what it does to men and places.

At One Point Brooks the Librarian says “All I Want to be back where things made sense and I want have to be afraid all the time” Why does Brooks say this? What does this attitude say about human beings?
Brooks has been in prison since before the 20th century really begun. He had done the same job, in the same place for decades. He had never seen cars, never seen electronic lights, he had never had a job, and never known how to do anything menial. He was used to being told where to go and how to do it. When Red is released, we are reminded that prisoners do not even know how to piss without being told when or how. Brooks is afraid, not of the dangers of the prison, which he has safely avoided for decades, but the strangeness of the outside world. If he goes back to prison, then the structures of official and unofficial behaviour that he has had completed for decades no longer exist, but the bare whispers of life before incarceration are forgotten.
He is afraid not of the dangers that he has faced and developed patterns for, but for dangers that he cannot have any knowledge of, not only how to deal with them, but how to identify them at all. For all of it's problems, the prison is orderly. What the film says about these things is two fold, and they are contradictory. It is saying that human beings do better when being controlled, that having too many options, of being too free after too much time not being free will result in the destruction of self.
But it also says, that a lack of personal autonomy will also destroy ones self. So Red and Andy, have the structure of the prison, know how to play it, and that playing the game in a way that is acceptable to most, results in a reward (escape for Andy, parole for Red). If one does not know how to function without the structure of whatever inside you are, then there is no centre, and if the centre cannot hold, then the resulting mess takes serious collateral damage.