I stand corrected on #1, Zimmerman ultimately opted to not use Stand Your Ground, he is simply claiming that he killed a teenager in self-defense.
Now that I read up quickly on Stand Your Ground, I doubt that Zimmerman could have won with that anyway, since he was not near his own domicile, and he was the aggressor up until the fist fight started.
Your point #2 is simply what Zimmerman said he observed, based upon his own biases, and is not as much fact as speculation.
Even in the worst case scenario that Zimmerman imagined, that Martin was "casing the joint", that in and of itself is still not a crime, and a cell phone photo of the suspect would have been all the action that was required by Zimmerman to document the event.
The fact remains, that Zimmerman was told that he didn't need to follow Martin, but he still did (probably because he felt somewhat secure with a loaded gun in his pocket).
Tell me, what would you do if your teenage son/daughter was apparently being stalked by an adult (not a cop), and your teenager tried to defend himself from what they thought was an imminent threat, but then the person pulled out a gun and shot them?
How would that sit with you if it was your child?
ADG