Tom enables other characters to change because he is dieing. At the beginning of the play, when Tom is Puck, he will "restore amends." You can see how Gwen reacts to the knowledge that Tom is going to die by looking at her attitude before and after the storm. After Coral runs away from Roy, meeting Tom on the beach helps her change again into a pretty well-balanced person (re: the playlet; "im walking, im walking") which in turn allows her to comfort Roy (who has never gotten over the death of his son).
Almost all the characters change to an extent. Coral and Gwen are the best examples of this. But Meg becomes more assertive with her mother (ie she acts like an adult) and Roy finally manages to release some of his self-control (when Coral goes back to him).
I dont think you could talk about change very well about any of the other characters (either their change isnt very dramatic or they are minor characters) but then again i think talking about 2 characters would be plenty.
My friend went to a lecture from Michael Gow, and he said that Tom undergoes change (he accepts that he cant use the fact that he is going to die to get what he wants - ties back into Megs assertiveness) but i think that is a pretty tenuous arguement.
in the essay, i reckon it would be best to talk about change in Coral and Gwen, and how Tom acts as a catalyst for the change. The shakespearian intertextuality (and other techniques) should probably also be at least mentioned. i think that is about as far as you could go, considering you have another 3+ texts to talk about.
i think fatmuscle put notes on the boredofstudies describing the changes that characters go through.
hope i helped. feel free to shut me down anyone
