You are too kind. Please believe me when I say that there are a lot of folks on this forum who know more than I do about Glocks, the only difference is that I can type faster than some of them!
I know of one certain way to reduce pre-travel, and that is to buy a trigger kit with the trigger pinned. Here is one: The "EDGE" Competition Trigger System - GlockTriggers.com
NOTE CAREFULLY that there is a version for Gen3 and Gen4. I have this kit installed in a G35 and it works perfectly, there's almost no pre-travel.