I don't think you need sway bars for a Travel Trailer (or Bumper Pull). Sway bars are usually considered needed for Truck Campers, or Slide-in Campers. Plus, are you sure your 2500 doesn't already have sway bars? In the rear, at least?
You are going to want to plug into 50amp service when camping if your camper is setup for that. If you try to "get by" with a 30amp service, almost inevitably you'll end up trying to use too much, tripping breakers, and possibly damaging something electrical.
NEED a surge protector? No, you don't need one. We've camped for 11 years without one, with no problems. BUT... if I was regularly using sensitive electronics (computers, etc) I would want a surge protector / voltage monitor.