Just off the top of my head:
The audition takes place in a theater. Nobody auditions in a theater anymore.
Bobby has a monologue that says his father told friends that his son had polio and Bobby makes a remark about "limping" for his father. The polio vaccine has pretty much wiped it out.
The show would have to acknowledge AIDS since it affected so many dancers.
If anyone ever tells you that you put too much Parmesan cheese on your pasta, stop talking to them. You don't need that kind of negativity in your life.