Can the front pads be replaced at 25% left and leave the rotors alone?
Does anyone use a scan tool that retracts the calipers? if so which one?

 

I would measure the rotors and make sure they are above spec and don't have a lip on the edge. If so you can do just pads. EBC reds are great
https://www.waymotorworks.com/ebc-re...rake-pads.html

No electronic tool to retract the calipers. The front you just compress and the rears you screw in.

You will need to replace the sensors.