I feel compelled to point out that the Glock has a firing pin stop. The "semi-cock" really doesn't matter. Even if you could somehow get the striker off of the trigger bar, it's simply going to hit the stop (presuming it has enough energy to set off the primer).

Trigger pull weight should be a non-issue in a confrontation. That is to say, you should not "accidentally" pull the trigger while pointing a weapon at a potential attacker, because your finger shouldn't be on the trigger until you intend to shoot. Really, anything in the 4-5# (or heavier, if you can shoot it well) range should be fine.

I know at least one..."seller of instructional services" (best I can do) advocates covering threats with your finger on the trigger, but literally everyone else in the industry agrees that, after testing the issue, there is no difference in reaction time between finger-on and finger-off.