2A is founded in the inalienable human right to an effective self-defense, regardless of oppressor. Oppressors encompass the criminals among us, outside forces and potentially our own government(s). Without the ability to defend your freedom, you have none that is yours. All you have is what someone more powerful than you will let you have by their action or inaction.
Florida is not exemplary of all the US, just as Switzerland, with battle rifles in many homes, has very low gun crime and violent crime, while the UK has more strict gun controls than DC and much higher violent crime. You cannot pick one place, time or factor and tell what the world is...it is like the blind men and the elephant.
John Lott took many factors and lots of data to prove his thesis. There will always be exceptions that prove the rule, too.
I am an extremist if you define one as being unwilling to give my life up without a fight. I would kill someone without hesitation if my kids were threatened. There are a lot of reasons to take that decision.
I would hope God would understand why I did what I did, and that in His eyes it was the right thing. He will decide the fate of my soul, and is my Master, not some silly Senator.
I think the least likely reason to go to arms will be a general uprising against our current form of government. First is the common criminal. second will be if and when radical Islam or a similar group figures they can start playing around as they are in France and elsewhere. While US police and military forces will react in that case, there will be some level of self-defense by citizens as the jihadis will not always hit where the police are (duh) and when seconds count, the police are at best minutes away.
Some look at the world as an ever-improving place, and I can agree with that in many ways. However, there is darkness out there. Evil does come knocking, and you can take an active role in your own rescue or you can hope someone will save you. For my limited exposure to violence and the limits of police protection, I think that is a losing bet, but do what you want.
Just let me do what I think is best for me (it's called freedom and "choice") and we will get along fine.