The first thing I always do is set the gun to its factory fast settings. Turn the eyes off and lpr all the way off. Turn it in a half turn as you attempt to shoot it. Once it fires smoothly turn it 1/4 turn farther. At this point I sharpie a mark on the lpr to ensure the screw is not creeping.
As for soldering its real easy as the contacts are rather large. I don't for see you having any issues here