Although I agree with 2 hands on the wheel, and have certainly gone through times when I got stressed, I think you need to get to a place where you are more confident and relaxed, Richard. You should be enjoying your coach on the highway more than it sounds like you are. I've driven ours for as long as 10 hours, stressed only during certain urban freeway areas, like Boise, Salt Lake, or Denver, or small town roadside trees, but relaxed through 95% of the drives. And though I won't touch a phone while driving, I'm certainly able to enjoy a coffee or a Coke.
If your coach is requiring a lot of micro-steering or is riding with an abnormal amount of vibration, than stop on your way to Newport at Grant's Pass, and have Henderson's check your coach out. Even if there's nothing wrong, you may find comfort knowing your coach has passed muster by the best.
Joel