What if anything can you bring in from the outside (catering, alcohol, florist, dj, cake etc).
Decorating options and limitations.
Extra fees (clean up, automatic tipping, etc)
Back to costs and food, if they will be providing your food and you're inviting kids ask about kids pricing and kids menus. A lot offer that but won't advertise it since they make a lot more money charging you the same thing for a kid that they do an adult when they usually won't eat half of what an adult will and depending on the food might not eat any. For my own wedding, I had kids pricing and a separate menu for the kids (foods they would eat).