Questions about our first (and big) trip

All I could afford wrote:
I have always been a strong recommender of the first trip being short and fairly local to learn the rig as well as your own needs and preferences. .....

I did not see the need for this. My wife and I bought the RV we wanted. After that, there were not a lot of major options. The heating, tanks, toilet and plumbing could not be easily modified. Electrical is a different consideration. We planned on boondocking and covering our needs without hookups. I was able to replace the old batteries with a couple of large AGM batteries. There was room for a second solar panel so I had that installed. I got a generator and worked out a system to store several gallons of gas. All the rest of the modifications were minor in comparison.