I agree w/nearly everything you said in your review.... except my High School (Boulder High in Boulder, CO) did do double casting: we did a straight play for the public and the purpose of double casting was that every single student in speech class had a speaking role for at least two performances.... It probably was a lot of work for the teacher/director but since she used class time for rehearsal I'm guessing she figured it wasn't extra work.

When West Side Story was originally being cast for Broadway they intended to have two Marias: a singing Maria and a dancing Maria. Carol Lawrence had to audition for both and worked really hard to convince them that she should play the role all her own self.

Anyway I was blown away by Mike Chang's 'Be Cool', that was really good. It is that kind of number that makes Glee such an enjoyable show.