Hi jayco26foot,
Thak you for the donation.
If there is any shorting in the compressor, you cannot control its running speed. You can only control the blower speed. When fuse keeps blowing, you need to check the cause and rectify it, sometimes is it due to bad connections and can heat up badly which can turn into a fire hazard.
R134A is of the correct spec so I don't see why it cannot be used.
To reface or replace rotors depends on the braking efficiency required. I don't believe everybody dirvies around with new rotors each and every time brake pads are replaced. I have replaced my vehicle brake pads at least 5 times but never did I once replace the rotors.