The trigger pull can certainly be lightened by the adjustment screw. It is a small ( 1.5mm ,I think ?) allen key screw inside the trigger guard. Unscrew to lighten.
As to polishing, I probably wouldn`t do it on a lightening. Firstly the sears are quite hard and fairly smooth anyway, and secondly, The triggerunit can be tricky to take apart and re-assemble.

Pete.