A- use the old pad with a c clamp to push back the piston. No need for special tool IMO. Just apply even pressure
B- the fronts are single piston where as the rears are dual piston with pins that hold the pads align. On the rears be sure not to removethe bolts which hold the caliper together there's four of them.
C- Ijust use the old german gutentight torque spec if you want to use lock tight I don't see an issue. I took off the calipers completely at 160k withno issuereusing the bolts
B- the fronts are single piston where as the rears are dual piston with pins that hold the pads align. On the rears be sure not to removethe bolts which hold the caliper together there's four of them.
C- Ijust use the old german gutentight torque spec if you want to use lock tight I don't see an issue. I took off the calipers completely at 160k withno issuereusing the bolts