Upload & Sell: Off
Your best bet is to get to the venue sufficiently early (at least 90 minutes) to have your questions answered by the person in charge. As you say, these things vary from venue to venue (and sometimes, from person to person you might speak to at the venue!). That's why you want to go directly to the source, and allow yourself lots of time to get the lay of the land. If you'll be transmitting images from the venue, that's another whole set of instructions, touring, etc. that will be required.