A fire department in our county was cooking a bunch of shoulders for a fundraiser a few weeks back and set their building on fire. It was quite embarrassing for them to have to call in a structure fire at their station. They were using a pit though, and had fired one section a little too hot. Just be diligent with your temps and you'll be fine.
How much propane do you end up using during the smoke? I've use a similar setup with my gas grill, but its hard-lined into my underground tank, so I have no idea how much propane I use each time I use it.
The restaurant has gone down hill, but their Pitmaster is good. Probably will do well on the show.
Where do you get your wood from? I think I need to find some bigger chunks than what I have picked up from Lowe's and/or Ace Hardware. The fist size chunks I have been using were turning to ash in about an hour and quit smoking while I had the butts on. Is that normal?