Personally I think they should have used completely unknown ppl in the movie. In a situation like this where the characters have already been designed and ppl have gotten to know them. Transfering their personality onto wellknow actors is a real problem unless the actor in question is either 1: Extremely talented, or 2: That kind of actor who doesnt have a certain "way" about him, the way Freddie got the Teen Movie deeply rooted in him.