Start mode is for how hard you want to put power down. Try soft at first if you like it and the motor works ok without starting stutter you are fine. Try the other settings as you wish and see if you like it to start harder. If it suits your driving style better and doesn't stutter at all you are fine.

Starting harder will also increase peak amp draw on start also

Timing mode depends on your motor. Someone coirrect me if I'm wrong. If Using lower pole motors and higher KV, lower inductance motors, lower timing. Adding more timing can help some outrunners & 4+ pole motors run better or properly if there is issues when trying lower timing.
Increasing timing can increase amp draw. Sometimes a gain in speed but, higfher amp draw.

Governor Mode is for helicopters only, its for holding steady rpms or something like that.

Hope I have helped.