RE: Where did I go wrong?
Just switch brands of servos; Hitec and Futaba turn in opposite directions with the same input. To change the direction of a servo, you need to modify its innards, switch the two outside wires on the potentiometer and switch the two wires going to the motor. If you interchanged the positive and negative leads on the servo you tried to modify, you most probably smoked the servo innards. If it was the positive lead and signal lead you reversed, no damage should have occurred, just switch them back and see if it now works.