1. The snap up brackets are pretty much universal. Try etrailer.com You can get a friction sway bar at the same place.
2. The battery will last 3 or 4 days as long as you don't run the furnace. With the furnace on you might get 1 day if your lucky.
3. Most TT's have 20 or 30 lbs tanks. One 20 lbs tank will last about of year of normal camping, again, minus furnace.
4. Never found a campground yet that didn't have a dump station, provided it's not rustic camping. If it has electric it'll probably have a dump station.
5. Find a campground with at least electric at the site and give it a whirl.
6. As long as you are not putting out the slides and the BBQ (basically just stopping to sleep) no one will probably bother you.