Tire Size ?
#2
It depends on what size are your rims and what backspacing they have. If you are using stock rims then you will have no problems. If you wanted you could put 35's on.
#5
you should be ok! But id recommend cranking up your torsion bars to level the truck.
Im not gonna say you wont rub theres too many variables but if you do it will be at full lock and the tire will rub the frame
#7