Once connected to your joystick in control options on the left you will find sensitvity settings although these are likely to be the same curves as you have already, if your stick has jittery potentiometers be sure to set deadzones for the neutral positions. Also when selecting an aircraft in the world menu you will find that each aircraft has a slider for rudder, elevator and aileron authority.
One thing to mention is that small aircraft are mostly very twitchy in real life, try watching a few YT videos of pilots in turbulence and you might well be shocked at how reactive they have to be. I know I was.
I hope this helps
Brian