This has always been my favorite movie... What I didn’t know until reading a biography about him, was that Richard Pryor was behind most of the writing and was intended to have the role as Sheriff but the Exec’s (and Brooks) chickened out.
I don't think they "chickened out". Pryor was in the midst of his substance abuse problems, and they were more worried about his erratic behavior.
Pryor did write some memorable scenes -- such as all of the ones involving "Mongo". I also remember hearing or reading that one particular scene was feared to be offensive to blacks, and Pryor said: "If anyone complains, I'll tell them that I wrote it, so shut up!". Unfortunately, I now can't find which scene that was.