How often or ever should the tires be rotated on a c ?

Nope. Mine are wearing pretty uniformly so they'll all be ready for replacement when the time comes.

If one end of the RV wears out first (like the front), you can just replace them and do the rears when their time comes. The adage about replacing all tires at once applies to cars but not so much for RVs.

Lots of folks' tires age out before they wear out anyway.

The purpose of rotation is to try to compensate for differences in wear at different positions, so that you can replace all tires at the same time, as a matched set. Uneven wear is particularly a problem with front wheel drive cars that are also heavy, so rotation pattern is front to back ( no crossing, for radials, some can handle it, others don't).

On a dually two axle truck, you might rotate inner dual one side with outer on other, or inner dual to same side front, or front with opposite side outer, and still avoid reversing rotation. Ford recommends only rotating fronts with spare, not worrying about rotation direction, to include the spare in the wear set, to replace those three tires at the same time.

I've watched for unusual or uneven wear on my tires, but in 30,000 miles, over six years, there was little wear at all before the tires needed replacement for age.

Interval? Oil change interval is roughly 5000 miles, I would consider doubling that on tire rotation, if doing it. Maybe longer, you could be looking at 50,000 to 80,000 miles of wear, before replacing because of tread wear.

I have heard as long as they are wearing evenly, leave them alone and that is what I do. Regards, Dick

I don't.
I have in tire TPMS sensors that are position sensative.