We had an RV for a while and have done several big loops. It's a lot of fun. You'll have to put up with all the other RVers complaining about the cost of gas, while you wonder what the heck they're talking about
The one part of your plan that I wonder about is Death Valley in September. Man, that would be hot. If it came on the heels of some cold weather stuff, maybe it would be welcome, but the rest of the tour is likely to be quite hot too. Last time we were in an RV in Las Vegas, it was 118 degrees, and although we'd planned to stay 3 nights, we fled after just one, choosing Newport Beach as the coldest location we could find!! Our RV had air conditioning, but it simply couldn't cope with that much heat....even full speed on the freeway.
I recommend approaching Grand Canyon from the west, not via Canyonlands etc to the north and east. On our first trip to GC, we approached from the east, through ever more impressive canyons, so that by the time we got there, it felt like "Oh, look, more canyon!". Approaching from the west is much more jaw-dropping.
Zone diet on and off for several years....worked, but too much focus on exact meal composition
Primal since July 2010...skinniest I've ever been and the least stressed about food