Okay, so layout limitations: how big, where can I put people, where are the egress, where are the exits, where are the entrances? What do I need to know about your venue?
Capabilities: what your AV, do you have water, do you have heat? What's included in this package, and more importantly, what is not included? Can I ship things there in advance, etc.?
And last but not least, restrictions: fire restrictions, dietary restrictions, sound ordinances. Ask all those questions.