RE: Rotor head setup
If you just want more response around center stick use expo, raising or lowering the % value +/- depends on radio brand, but one will soften and the other will increase input, to get a linear feel, up the servo travel value beyond 100%, which is similar to uping swash %s.
Expo's probably the answer, to avoid binding.
I now a DX7 linearly processes upped ATV/EPA values like uping or lowering the travel value in the expo menu. Be aware with the combination of the two/three (swash values, expo values, and EPAs) it is possible to overdrive a servos potentiometer.