More random observations:
ACA Northern Tier, Washington 20: I'm glad I had two months' riding in my legs before I tackled four passes in four days.
ACA TransAm maps/route was invaluable getting across the Ozarks in Missouri and eastern Kentucky. (You are in a maze of twisty little passages, all different...) With some experience touring, you can probably pick out good routes most of the rest of the country.
I wonder how local police would respond to a request to park on the town square or park overnight in an RV. Probably depends on the town. I've heard some Walmarts now turn overnight RVs away, but a personal request to the manager might mitigate that.
Having a support vehicle would make it easier to ride an extra hour in the evening, knowing you can be picked up and taken somewhere else for the night. You could arrange a water resupply every 30 miles in the dry spots, too. But don't forget the local diner where you'll meet half the down for lunch!
There's probably a balance to be found between locating local attractions on your own custom-generated route and tying yourself down to a specific route when you find the road is under construction or there's a bridge out.