Things that affect handling:
Tire pressure, The pressure written on the sticker inside MIGHT be right, under one set of conditions, but I'd say there is about a 1 percent chance.
Likewise the pressure mentioned on the tire. But a slightly higher percentage.
The only way to get it right is to have the thing weighed, 4-corners, and inflate per the tire company chartes, RV Safety & Education Foundation
has a link to folks who will come to you with scales for the job. This is the EASIEST option, but not the only one or the cheapest.
Alignment: You need a truck quality shop.
Stablizer, Well, you know that did nto do it
Track bar.> These make a big difference
Sway bar... Not all coaches need these.
Sway is rocking side to side like the people holding up lighters or candles at rock concerts swaying from side to side.
If your chassis is either Ford or Workhorse, Barzil's rv and Redlands RV (if you are near either of them) sell the Ultra Power rear track bar.. Appears to be well built, quality product.
I have a Davis Track Bar on the front.. I'm told a rear bar would give better results but let me tell you I'm impressed by the one I have.