1. Secure your trailer as best you can. The trailers themselves are not built very secure. If somebody wants in, they're getting in. When you go to travel somewhere, you don't want to drag your trailer everywhere with you. It's part of the deal; drop the trailer, secure it as best you can, and go. IMHO, I'll always find a campground to leave the trailer - even if it's only for a day. I feel much safer with the trailer at a campground than I would in a parking lot.
2. See Answer #1.
3. If you have a big enough truck, get a 5th wheel. No real advantages to a Travel Trailer over a 5th Wheel - except for truck size.
