Are you asking about the switch settings? They simple change the range of the gain setting. Gain is the "P" in PID. Unless you have a reason to change it, leave the switches in the default positions. There is no "at rest gain". There is one, and only one gain, adjusted with the Gain potentiometer. The Torque limit has nothing whatsoever to do with PID setting, it is simply a motor protection feature. What all these settings do is explained rather well in the G320x user manual, but it sounds to me like you don't have a good understanding of how a PID servo loop operates. But, if you follow the tuning steps in the user manual, or the G320X FAQ, you should have no trouble getting it working.
Regards,
Ray L.