1) No personal experience with Keystone, but owners I've talked with seem happy with them. We seriously considered that exact model, but with our kids being 16, 13, and 13, we only see another year or two of family camping.
2) At the min, you want a WDH with sway control. Or even better, a dual-cam anti-sway setup like the Hensley Arrow. Otherwise, an Excursion should be GTG.
3) It all depends on your comfort level. Most campgrounds are built to accommodate large rigs, and many have pull-thru sites. Personally, I enjoy the occasional challenge of parking my rig. I've logged over 20,000 miles of towing, so I'm used to it by now. I also pull a 12' cargo trailer. I actually prefer backing the TT compared to the CT. The TT doesn't jackknife as easily.
One of our first trips was to Ft. Wilderness. We got a spot in the 100 loop, it was a back-in site, and there were many cars parked on the side of the road. 9.5 out of 10 on the level of difficulty. I could see some of my neighbors getting out the popcorn to watch the show. Challenge accepted. Docked the trailer in one smooth motion. I was very proud of myself.
