We did exactly what you are proposing on several long trips. We don't pull a towed vehicle still, but we do put a XT250 on the back hitch mount for good weather exploring. With the stock cameras, a 31' can go just about anywhere.
Yes, you have to do some backing up and some 5 point turns in tight lots. First thing I look for is the parking lot. Just park a long ways from where the crowd ends and walk a little bit more. For most situations, I would guess a 34' would be fine.
However, coming out of parking lots onto the street is the one weak point of having a longer model, because of the rear end scraping. Also, coming out of everyday gas stations, the rear end swing is something I have to watch even with the long wheelbase 31' model.
When we went to the Tennessee mountains, I had to cruise completely through Sevierville in order to find a place to turn around, though. I was driving our handicapped daughter, who is most comfortable in the RV, but enjoys driving around seeing things.
So sometimes, if the parking lot isn't roomy, I have to pass up a place, but we can go get anything we need with the 31', and probably with a 34'. We also got the 31' to pull a 28' trailer and stay at 60' total.
I like the quick disconnect features that you can add to the motorhome, so that in 20 seconds, you're unhooked, another 30 seconds at the wheel for the jacks to come up, and you're rolling. Driving by myself, it would be very difficult without the backup camera working, though!
With the 31' the only gas station limitation is the height of the overhang, too. Again, if it gets tight, just back up a few feet, move over a little, try again, all slowly.