Here is an old MT thread that includes good questions to ask schools that you have been accepted to…its a cumulative thread so worth reading all pages. Of course, it’s MT so some may not apply, and everyone has different priorities so you may want to choose five questions to ask all schools just to narrow down which ones you will actually visit. Also, you can search school names here and find students, parent and alumni of schools and PM them and ask if they would be willing to answer questions to see if you get the same answers/opinions. And of course, I would include your waitlists in that list! But, First check websites where you might already find answers to some questions:
http://talk.collegeconfidential.com/musical-theater-major/1624534-questions-to-ask-during-the-campus-visit-p1.html