I did not read all the posts. When I get new tires for the camper, I always have them balanced, even though "they" say it's not necessary for a trailer. I tell them I want them balanced anyway.
Oh, the trailer still shakes, rattles, and rolls. It bounces, it vibrates, it shakes when rolling down the road. Regardless of the suspension, it's still an earthquake in grand scale going on "back there." Every time a transition joint on the interstate is hit when crossing a bridge, I can hear and feel the trailer pounding down on the truck. Yet, I find it interesting that a cup of water left on the counter will still be sitting there. Or an ink pin will still be on the counter and not on the floor, but a piece of furniture will be on the opposite side of the camper.