As far as rotating, I have been told by more than one tire shop that the old warning about rotating radial tires; that is only go front to back, never cross, is no longer valid, and many tire manufacturers now recommend rotating as follows (for a rear drive car):
Drive wheels straight forward, non-drive wheels cross, and back (e.g. right rear goes to right front, right front goes to left rear, left rear goes to left front, left front goes to right rear.)
Anyone else heard this, or doing this? I have been doing rotations this way for several years with no apparent detrimental effect.