Perhaps. But he could also have feared for his life and was fighting to defend himself. We'll never know because one side of the issue is dead and the other side are under arrest.
Yes. I have been making that point.
He could have charged an armed man because he was an innocent man in fear for his life. But that's something I would do only if I was CERTAIN that I was about to be killed, and thus had nothing to lose.
Alternately, he charged an armed man because he was a criminal on probation, and realized that he could not afford to be arrested again.
The rationality of assuming whether you are in danger depends on the circumstances. If I was on foot in an "inner city" area, and some openly armed men said they wanted to talk to me, I would have a much different reaction than if I was in a middle-class suburban neighborhood and some armed residents wanted to talk to me.
It's very politically incorrect to make the above distinction these days, but reality is that I would be in danger from minority underclass people, but not in danger from armed middle-class people. Underclass thugs kill people routinely. Middle-class home owners don't.