For me Cal is a "coward". I mean he is not abel to say that he doesn't wanna help Crilly etc. and then he can't tell Marcella what he had comitted.
And in the end he ran away and just sitts around waiting for the police and he is still not abel to tell Marcella the truth ...
In my opinion there is no chance in the book and I can't identify with such a person. So I can't "like" this character

and I think - to give an answer to JJJ first question- it would be hart to performe it on stage because I think that you are not abel to show all the places where it plays- but they are all importent.
It would be easier to make a movie about the book.

I agree with you. I thinkt that "Cal" doesn't show many of the aspects which are mentioned in a typical classical drama.
It just can be played as a sort of a modern drama because the book is writen as a novel and like Max R. allready said the book (plot etc.) doesn't fit in an classical drama.