You can learn QLab basics in about ten minutes. At its simplest, just drag and drop your sounds into the cue list. You'll save yourself a lot of heartache if you take a tiny amount of time to check it out. I've taught complete amateurs how to use it in half an hour and as you're an experienced PT user, it should be a doddle.
Still confused about which walls the speakers are on, though. As far as the snake is concerned, the previous poster is right; just feed a signal into the desk and connect each of the snake connectors to a live output of the desk. That should show you what's connected and what isn't. Is there some form of speaker management system somewhere in this hall? Is there a rack with amplifiers to drive these six main speakers, or are they self-powered? if so, you can just connect up the first pair and then daisy-chain out from one to the other: (balanced line interconnects, of course, and you may find that one set has a band-passed sub output.) If there's rack, then the same thing applies; daisy-chain if you can, so that each speaker has its own amp channel control. The more info you supply, the more we can help.
Best of luck,