I surely do not know if it is needed but I do when I repack the bearings each year. Not that I have seen any more ware on one tire or the other just thought it would not hurt. I move the front to the back and back to front. Just make sure read the correct procedure on jacking the trailer not to damage the axle.
George and Debi
2006 F250 PSD, 2005 PF30CK
I am a firm believer in balancing them. As far as rotation IDK but can't see how it would hurt. Recommended on your TV every 6000 miles. If you are not putting those kinda of miles on them and don't have wear issues I don't think I would bother.