I would think it would be easier to adjust that in the radio. (the travel distance, that is)  Remounting servos seems like a PITA.  recenter servo arms, adjust control rod linkage and length to center the control surfaces seem easier to me.  Perhaps a rod got bent.  Starting from "scratch" by remounting the servo and linkages would be a last resort in my opinion.  But as a disclaimer, this is my first season in this hobby, I could be completely wrong

As far as throws I went 1/2 inch each way on ailerons and elevators, 1 inch each way on rudder.  17% expo on elevator and ailerons and 25%on rudder.  During the sportsman sequence I did not "max out" the surfaces at any time.  Not even during the intermediate sequence either.