You're drifting away from your original statement/question/ You were asking what was stopping Zimmerman from using his weapon to question Martin. You're argument was that since Zimmerman wanted Martin questioned so badly that he would have done it himself using his weapon.
Archer, you're a good guy, and you don't melt, so let me carefully explain this to you.
No. The idea is not that Zimmerman "wanted Martin questioned so badly that he would have done it himself using his weapon." Again: No. The argument is that Zimmerman would have used his advantage of being armed in order to cause Martin to stick around for the arrival of the police.
So...
We know Zimmerman had been taking steps toward accomplishing what is a VERY, VERY, VERY IMPORTANT objective in his mind . The question is WHY would he choose NOT to use every advantage to fulfill the objective. Can you conceive of ANYTHING that would fit this, Archer?