How is the setting important to the plot of the story?

The setting of this novel is a major part to the plot of this novel. Catcher in the Rye is set during the late 1940's to early 1950's, around the start of the war to the end of it, in New York City. This creates a very different dynamic compared to current day. The time frame is important to the plot because Holden does things that he would not be able to do if he was trying to in the present day. To start off, he leaves Pency Prep a few days before he was really supposed to leave for Christmas break. In present day, his parents would've been told instantly that he is skipping. Him being aloud to leave is because of the setting, meaning that the rest of the book wouldn't even be able to happen. 
Another reason why setting is such a large part of the novel is because he shows that he has mental health issues that we as an audience now can see. During Holden's life there is no awareness that mental health is even a thing, everyone thinks that he just crazy and cannot be helped. A lot of these problems come from when his younger brother Allie passed away. If the setting was different than Holden would of been able to get help and maybe would not have such crazy problems.

What effects do the events have on a particular character's life or personality?

In the Catcher in the  Rye, Holden has one major event early in his life that changes his entire view on how he will be in the future. This event is of when his younger brother Allie dies from leukemia cancer. at the time Allie was only 11 when he passed and Holden being 13. Holden and Allie were very close with each other as they did everything together as well.
It was at this moment that the happy and average boy that was once Holden turned into the mea, depressed, ignorant moron that we know of with in the novel. If this event never would've occurred, perhaps the events in the Catcher in the Rye would never had happened.

In what various ways does the narrative viewpoint affect the text?

The novel is told through the eyes of Holden, therefore it is told from the first person. The biggest way this viewpoint affects the text is that every opinion and situation is told through Holden's perspective. This only allows the audience into only thinking in Holden's way. This does not necessarily hurt the novels quality, just changes the audience's perception of other characters and situations. Perhaps the biggest example of this is when Holden calls everyone phonies. This is constantly just stated with no knowledge, the audience only knows that Holden thinks they are fake and since this is the only piece of information we know, this opinion becomes the audience's own.

What do you think is the climatic moment of the text? How is it a turning point / a resolution / a switch in the balance of power?

The major turning point in this novel is when Holden decides to leave Pency Prep.  His location of choice to recuperate is the Big Apple, aka New York City. This is the most crucial part of the story as it is when Holden's life is completely changed. This one decision was the beginning of Holden's long journey of self discovery and contemplation. Without this crazy decision, the rest of the novel would be non-existent, making this moment the major turning point  of the entire story.

When things start to change

How do characters change or evolve throughout the course of the story? What events trigger such changes?

For this question I will focus on Holden Caufield character for this question. Holden's character is quite interesting and confusing. Much like his emotions, Holden's personality is very scattered, which makes it incredibly difficult to observe any change or growth within him.
 However, what could be discussed in this question is Holden's personality prior to the time frame of the novel. As many people who have read the book know, Holden had a younger brother named Allie who sadly died at a very young age. Upon learning of his brothers death, a young Holden went into a rage mode and proceeded to smash the garage's windows out with his bare hands. He never wanted go for help to accept his brother's death as he would say that he's okay.
This one moment changed his life completely, as he changes from an unassuming normal and kind boy into a depressed jerk who goes around hating everyone and everything in the world. Holden's one sided brawl is a top example of his character going through an enormous change.

Chesser told me to type this