1 I don't know but would assume yes.
2 I carry a compressor found it easier to get a chuck with a different angle.
3 You don't want wider tires.
4 60,000 miles on my A/T Rugged Trail duals, 50,000 towing 5th wheel 3200 pin weight. The right rear outer dual shows a little more wear than the inner and the driver side are equal. I keep them all at 65#
Just a question how often do you ride on the crown of the road? Most roads I've ever been on will slant a bit to the curb for runoff. If that is correct it could explain my rear outer dual showing more wear than the others as more weight is shifted to the curbside.