CPshooter, as far as the trigger hurting the finger I think that is the biggest impediment to shooting a Glock repeatedly, quickly, and with accuracy. As soon as I get one I lop off the two tips of the trigger rendering it flat, then shave the trigger safety so that fully depressed it is flush with the trigger. It takes a sharp knife, a little fine sandpaper, and 5 minutes.
As far as pull weights, There are a plethora of options. I use a Ghost Rocket #5 connector in my carry Glock along with a heavy trigger bar spring and a standard striker spring. Combined with some careful polishing, good grease, and keeping the striker channel clean I have a crisp 5lb trigger, it takes up much shorter than stock and thanks to the overtravel stop on the ghost rocket the reset is verrry short. I can shoot way faster than I can think with that trigger.
My play Glock has a #3.5 in it, reduced striker spring, heavy triggerbar spring, polishing and a few other things. It strokes more like a very light DA and breaks at 2.5lbs. I could get it way less, but it scares me.
As for trading out springs and such, keep stock weight springs if you are going to carry, no sense in reduced power springs causing reliability problems.