You are smart to take it slowly. There's a huge difference between a car and a giant RV, and it will take time to become a safe and comfortable driver in all of the varied conditions encountered on the roads. If you're not doing it already, try using Google Earth to select a good route for yourself, until you get more practice. It only takes a few minutes to check hundreds of miles visually for any surprises.
For now, you could stay mostly on the interstates, but try including a portion of each trip on a smaller road, allowing you to gain experience, a bit at a time, without making the trip painful for yourself. Each time you go out, go a little further on the side roads.
Be careful not to let other's bravado push you into something you're not comfortable with, remember, this isn't a job, it's supposed to be fun!
For me, it's pretty simple. The reason they have quiet time is to provide a time when people know they can sleep. This is especially important for tent campers, because tents provide absolutely no barrier to sound. During quiet time, we either go inside, or keep quiet.
... They have not come up with a good way to stop them. ...
But yes, there is a good way to stop them. People must stop buying things from them. At least for the sales pitches, the only reason they call is because some people will buy their product. If no one bought, then the sales calls would disappear.
Do your part, spread the word, NEVER EVER buy anything from a telephone solicitor, then they will go away.
...I agree with his prior statement that going 55 is a far greater hazard on the interstate. 90% of the traffic is around 75, 55 is a rolling obstacle. I would have loved to travel 60, even that was dicey. People closing at 80, side by side, trying to find the passing lane before rear ending me, semi's passing, etc. To ignore the median speed of traffic and how a person towing fits into that is assinine...
Surely you're joking. Any driver who's so hopeless that he can't manage to safely pass a vehicle with a closing speed of only 15-20 mph, is certainly so incompetent that he's going to crash into you no matter how fast you're going.