RE: control horn
Probably not. The instructions should tell you the correct throws, and then you put the pushrods into the holes that give you the right throws. If you are using a computer radio, then you can set it up for max throw, and then limit it via your radio.
As a starting point, I usually go about 3/4 out on the servo horn and 1/2 way on the control surface horn, but set it up for the recommended throws per your plane's manual.
Good luck