@GStrot list is excellent
We asked about security, how many of the emergency call boxes they have, how quickly security can respond etc. Also at the dorms, is there someone checking IDs at the entrance, how many entrances have access etc. Do they allow overnight guests in the dorm rooms, how is that policed.
Is the cafeteria tupperware friendly, access at most college's is based on swipes. X number per week. If your kid wants to take something back to the room for later(snack or lunch or something) it can save them a swipe. Some places frown on bringing tupperware to the caf. Meal plan is expensive, want her to get her moneys worth.
Are text books available online, are they available at the library
Ask if they use an online portal for assignments, most places have something. Are they ok with paperless options to turn in assignments(my wife is a recycle nut so she always asked this). Make sure if the kid goes with a laptop that it will work OK with whatever portal the school uses. Really shouldn't be a problem but worth checking. They will try to get you to buy a laptop from them with a service plan at the college included. We didn't do this.
I would always chat up the tour guide while we were walking from place to place. I think I got the best(most genuine) info just shooting the #### with them. Mostly upperclassman so they let their guard down when they aren't giving the typical letter head speech.