I’m saying in the real world you don’t go looking for trouble. When I was young and went to bars, all you had to do was say the wrong thing or look at somebody the wrong way, and you were in a fight. Maybe I’ve missed it, but it appears this kid had a legitimate reason to be in the neighborhood, and was not observed doing anything that indicated criminal intent. Maybe trailing people you don’t know in your neighborhood with a gun was normal for Zimmerman, but it was nonetheless provocative. It was probably inevitable that eventually he’d run into some kid with an attitude and either Zimmerman would be dead or the kid.
Yes, you missed Zimmerman's call to the police where he describes Martin's behavior. As far as citizens carrying guns and watching out for their homes and communities we have the 2nd Amendment. Militias are a principle enshrined in the Bill of Rights.
Looking and reporting is what neighborhood watch people do. Criminals do take violent exception to their livelihoods being threatened, so neighborhood watch people are taking a risk, which is why some of them are armed. In the past month, the gated complex (with gate pass codes but no private security) had had half a dozen burglaries and a home invasion.
You are apparently gravely ill-informed.