Actually, you can run the generator, therefore the A/C, as long as you like, when you are in a place with no timing restrictions. A few years back I was at Oshkosh (the big EAA convention in Wisconsin) and camped in their camp (no hookups, in a generator permitted 24 hours area) and ran the genny for something over 72 hours straight, because we needed the air conditioning. That wasn't the first time, either.
The generators in class A rigs are designed to do exactly that, and a device such as the Gen-Turi hooks to the generator's exhaust to direct it upward and get it away from being a problem for you or for others.
While this can be a problem, it is fortunately very rare, so long as you're careful where you turn -- you learn quickly. I've had this problem perhaps four or five times in the 10+ years I've been towing a toad with a class A.
You lose a little, but not much, and not nearly as much as in a class C. You lose so little because the driver and "co-pilot" seats swivel around to become part of your living room furniture. And you gain storage space over most trailers I've seen of similar length, as well as having a built-in generator rather than having to either do without or to buy some form of portable (and to manage fuel, as well).
A rig like mine comes with 8 batteries and can easily boondock for a week just by running the genny a couple of hours in the morning and again in the evening. But if you are going to do a LOT of boondocking then adding solar to something like my Ventana would be very beneficial and, depending on what you added, might drastically reduce or (mostly) eliminate running the genny, unless you need A/C.
In most cases a spotter is needed (IMO) as much (or as little) with a motorhome as with a trailer. You can soon learn to back a trailer, with a bit of practice, and backing a motorhome isn't necessarily a piece of cake just because it's one piece (you DO need to unhook a toad before backing). It still is taller, wider and longer than you're used to, and can surprise you with the path it requires to back in to an area (or to turn a corner on a tight corner of a road, for that matter)
If you passed your CDL, then either way will come quickly, with some practice, probably in a large, empty parking lot, perhaps with some orange cones to mark parking places or obstacles to practice with.
Luck...