Are the rotors supposed to be turned every time you change pads. Everyone has a different opinion on this. Some don't think you should because then the rotors lose thickness and warp easier. I kind of think my new pads glazed over. In the beginning the truck would stop a train, then after a while you had to press a lot harder on the pedal.
A shop will normally replace the rotor when they replace the pads. They don't want call backs.
Torn boot - it needed replaced.
While a torn boot can be replaced, the piston would need to be inspected and bore inspected. A mechanic will just replace the caliper.