Hey, It's That Guy!: The two most prominently featured students in Robin's class are played by Robert Sean Leonard and Ethan Hawke while they were still "that guy"'s. Or put another way, Doctor Wilson "cancels" his plans of a future medical career after a brutal putting down from his asshat father Clarence Boddicker. He is only slightly nicer to his other son, Eric!
An earlier draft of the script included Ginny Danbury, Chet's sister and a friend of Chris's. Along with giving Chris more screentime, Ginny also had the role of Hermia in the play and the actress who played her, Lara Flynn Boyle, still appears in those scenes even though the scenes with her as Ginny were cut. Even though those scenes weren't technically necessary for the rest of the movie, it would've been nice for Chris to have a friend outside of her love triangle with Chet and Knox.
Liam Neeson and Dustin Hoffman were considered for the role of Mr. Keating.