"I only want guests to have wireless access only from the area/building in which they will be visiting."
I can think of two ways of doing this ...
1. Create AP Groups. This method allows you to broadcast a specific SSID in a specific area.
2. Each Lobby Administrator can only see the account created. Lobby Admin 1 can't/won't be able to see accounts created by Lobby Admin 2, for instance.
Hope this helps.
3. Lobby Admins must be strict. Do not allow them to create 31-days account (no time limit).