RE: New Giant GP Super Sportster!!!!!
Essentially, yes. But because the servo moves in a rotary pattern, 140% doesn't give a lot more linear movement to the pushrod than 100% and you wind up with reverse exponential travel toward the higher %. You can balance that out by offsetting it with the expo feature of the transmitter, but for most purposes, 100% is a good number. Once you have set the high rate mechanically, you will need to set the low rate on the transmitter (I don't know of any other way to do it), but if you find that you never use the high rates, it will be beneficial to go back and reset the travel mechanically to the low rates (or whatever rate you like best).
Servo torque is given in inch/ounces. If your pushrod is 1" out on the servo arm, the servo should deliver it's rated torque to the pushrod. If you move the pushrod in to 1/2" on the servo arm, the servo should deliver twice its rated torque to the pushrod. The closer you can get that pushrod to the center of the servo arm, and still get the control surface travel you need, the more power the servo will deliver to the pushrod.
And yes, always use the farthest out hole of the control horn. Leverage.
Jim