I am not reading this thread, it is too long.
here's my personal opinion.
The SYG laws are stupid, IMO. I think it was very difficult to prove murder 2 because of Florida's laws and for that reason I can understand why he was acquitted. Having said that, I fully believe he is responsible for the death of Trayvon, I fully believe his actions were negligent to start with and that he lost it and killed the kid, likely in cold blood (the latter not without a doubt). Should have at least gotten manslaughter.
If the laws allow someone to ignore police order to restrain from approaching someone who had committed no crime and then you do it while holding a gun, create a bad situation, and kill them, you are responsible for the death. Period. You should be in jail.
But, it's Florida...