When can I resume regular exercise after scar revision & mole removal?

Depends. Obviously, scar revision/mole removal on the hand would require longer rest of the hand than the same surgery on the face. Also, if the scar/mole was quite large and the skin was pulled tightly, more rest is required than if a narrow scar / tiny mole was removed. Ask your surgeon so that he can give you an answer specific to your situation.
Depends. on the location of the scar revision and mole removal, how deep the surgeon had to go to revise the scar, ... You should ask these questions to your surgeon.
Varies. It depends on the area and if it was cut out. Restrictions are for prevention of scarring. Discuss with your doctor.