i would put lightening the trigger on the top of the list. for a COMP gun, for carry i'd leave it be.
I've heard you can tighten up slide/frame fit by gently squeezing the slide in a vise. this also sounds like an excellent way to ruin a perfectly good slide, so proceed with caution. tight slide/frame fit will also improve your trigger slightly. if you unload your gun and slowly squeeze the trigger you'll notice the slide moves relative to the frame slighty as the trigger parts act on the striker.