Update! I finally took the improved rig out for a good long tow. 178 miles into the middle of nowhere Iowa. I put on new tires Load range E adjusted to 65 rear and 60 front, adjusted the roadmaster set up which had not been adjusted by the original installer, reset the WD hitch using a YouTube video from Curt and installed a new sway control friction brake. She is very solid now and predictable when crosswinds pick up. I had no problem in 30 mph gusts and it never even twitched when we hit the interstate and got passed by semis.
The better rated tires even improved the regular ride and handling immensely.
Thanks again for all your help. Without this solid advice I could have spent a ton of money on upgrades. As it worked out the investment was pretty minimal.