Questions for the Interviewer

I like to ask about alumni. You can take it in many directions.

eg if its a student "how much have you interacted with the alumni and how important are they in the job search process?"

eg if its an adcom "how do you reach out to alumni to keep them involved?" etc etc

Also, i think it was helpful that my answers to the basic questions I ususally discussed my sources ie alumni, talking to students, class visits, so by the end of the interview the interviewer actually said something like "you already know so much about our school and have talked to so many people you probably don't have any questions" so I can get away with just asking 1 or 2 questions that are more insightful rather than 4 or 5 'basic' questions.