Okay. I can agree that split second choices can lead to poor decisions, but we have to be specific here. Not being obligated to retreat is not the same as a free pass to kill anyone whom you consider a threat. However, I would argue that the inability to defend oneself could also lead to grieving families. I would wager that, even though a few police make mistakes and shoot someone who didn't deserve it, most police officers never make such a mistake. So, how do you determine whether or not a person would be able to successfully determine what is a legitimate threat and what isn't? This is something I can't answer, and I doubt you can either, so we'll have to leave this one up in the air.
I have to agree with that first sentence of your second paragraph. Hell, I'm a great example of two out of three of those points. However, all self-defense revolves around lethal force being the last option when all else fails, and I believe that the stand your ground laws had that in mind as well. If they fail to convey that, then they need to be amended to make that more clear. The problem with self-defense is that outside of your own home (assuming castle doctrine applies where you live) you are put in extreme danger by the laws themselves. It is difficult for me to put into words right now, but basically, it is very easy to not meet self-defense criteria unless you keep your wits about you. This is conjecture, but I don't think that the moment that your life is being threatened is going to be the moment when you are going to have your clearest thinking.
Much of what you state towards the end is common-sense. If you go down the dark alley with the drug dealers in it, you're asking for trouble, sure. However, the way I view this law is that if someone pulls a weapon on you, you should have the right to fight back immediately, without attempting other options, if fighting back immediately seems like the best option for preserving your own life. It should be noted that stand your ground doesn't only apply to lethal force.
Honestly, to me, stand your ground laws seem like castle doctrine applied to locations other than your home, and many of the same arguments can be applied to both laws. I really don't think that the recent problems with stand your ground in Florida have been to due a problem with the law itself. I think that it is more due to the over-publicizing of people attempting to abuse a law that has every right to exist.
Sorry in advance for any ambiguity or choppy thoughts.
Edit: You should mark points that you edit in.