Like you I've never seen much point for running the AC on a generator. I mainly need the AC at night to sleep when you typically can't use the generator. If I was going to just sit in the RV during the day with the AC on I'd just stay home. Having said that, my TC did come with a gen. and I have used it on occasion to run the gen. for brief lunch or child nap stops when traveling. If it wasn't built in (meaning I had to drag out and hook up a portable) I probably wouldn't bother.
The Honda or Yamaha inverter generators are the only 2 that would get my money. Their reputations are nearly flawless. Everything else is a little cheaper, a little louder, and a little harder to get parts for, etc.
Your RV converter should charge your batteries fine it's a fairly modern 3 stage design. Otherwise, a good external charger might be better. I'd probably just upgrade the built in unit before I spent money on a separate charger. By the way, the "battery charger" output on a generator is typically useless: very low power and poorly regulated.
A 30A RV outlet on a generator is certainly a good selling point. I'd be fine with just a 20A however. I frequently camp at small campgrounds with 20A service and my AC runs just fine. I do turn it off when running the microwave.