I just read through the thread and figured I would weigh in with my thoughts, as @Dan Seven said- some good food for thought. If nothing else we can agree that despite our collective differences & approach we at least can be civil and discuss them.
With regard to violence and the potential for violence in our society, point by point-
1) Statistics show that we live in a safer society, that said, I don't put much stock in statistics outside of murder due to the onus being on the victim reporting it. I have been attacked in the past and frankly I didn't report it to the cops. Maybe I was wrong but living in the UK- street violence is common, especially on a friday night. Murder is rare however and we should be aware that less murder doesn't mean less violence- just less murder.
I like to think we as a society have learnt to get along better but in my experience people are nice and polite when everything is going well. Throw in some chaos and you will see things get crazy pretty quickly (my experience on the matter).
2) On the issue of fighting back & the definitions of the act- my stance will echo @zackmars on this, if my family (or myself) is in danger, I will end the threat. "Others" can quibble about the definition, is it murder etc. but I won't give it a second thought. My stance is based on the concept of personal responsibility. I do not go out and look for trouble but if you break into my home, you made a conscious choice and the consequences will be on your head- not mine.
3) On the religious aspects- please see rules. I know that politics, God etc. can bring up strong sentiments in people but sadly for us as a species we will never know with absolute certainty and this creates a situation where we turn on each other despite all the things we have in common. Toxicity is the bane of all internet forums and I aim to be autocratic on the matter- as @KCM said- we self moderate and do not censor. Having strict rules that apply to everyone regardless of "side" or belief, allows us to not have to censor which makes my life much easier.
4) On living with our choices- storytime: when I was 15 or 16, I worked at a supermarket part time after school. In the UK with (used to) have an epidemic of anti-social goons called chavs that would pick fights amongst other unsavoury activities. One night walking home from work, I ran into a group of these idiotic li' thugs- they tried to pick a fight with me but I walked away because frankly I was tired and wanted to sleep.
A week later, the local newspaper reported that an Asian girl had been raped in my neighbourhood, the same week I walked away.
I will never know if it was the same gang of idiots but the reality is that if you are passive with predators- they just become more confident. I felt a wave of crushing guilt and I swore on that day I would never turn the other cheek. If I had taken them down a peg (or two) perhaps things would have been different. Maybe it was all unrelated, we will never know (attackers were never found).
I firmly 100% believe that apathy is cancerous to society, by doing nothing we tacitly give free run to those who may hold contrarian ideals. Much like democracy, it only works if we partake in it. If we want the world to be a better place, we need to stand up and be counted- because those who want to abuse society most certainly do not have any qualms about doing what they want. And thats the crux of the issue.
This is not to say we should go hunting for thugs- but rather when we see something wrong, we act. Even if we risk being put in a questionable situation.