I am not sure how did you make the number of 12, but this what you wrote... Let's see the scenerio, which would work according to my thoughts right.
In a small Czech city, a hunter sees a lorry driver running into people and other cars with his lorry. The hunter, then, can take his gun and shoot him to safe the people the mad man could eventually kill. (this is a real event, which took part in my country a year ago, the man was drunk)
How this would play correctly according to your words
The hunter would see a mad man running with his lorry into the people and other cars. He calls the police. Police calls the independent judge. The independent judge will cast a decision in 6 months (this is pretty fast for my country). In a meanwhile, the dangerous man will kill many innocent people, but he will survive.
The hunter killed the man. It later turned out that it was a drunk member of one minority famous for avoiding the work, rudeness and agressivity. Before he shot, the man did destroy many cars. There was no guarantee, he wouldn't cause any more damage if he was not shoot. And a police would not be there sooner than in 10 minutes, which is enough for exploding a bomb. Nobody could know if the cargo is safe or just a huge amount of TNT. I deem it correct behaviour. I am not sure how better you want to solve, when you are directly threatened at the present moment and waiting for men of law could be a risk for your life or that of your friend's, neighbours or other citizens of the country.
Which is what I mean by taking justice in one's own hands at a time. Of course, he will have to proof he did good. We are agreed on this if I understand.
Alright then. We are likely not agreed. I am not lawyer, so I didn't know the exact definition. It will likely be different in various English countries, I bet;
Self-defence includes defence of others in my country's law. Going away from that example, which was, by the way, investigated as murder, not self-defence.
If a regime forbids you to spread the truth people should be aware of (from your perspection), is it bad to spread the truth? According to your definition, Edward Snowden did bad. According to common sense, well, depends on the person. But I quite admire him and consider it good what he has done.
Another good example. Just re-reading your definition and seeing this "One day, after years of violent abuse from her husband, she took the law into her own hands." If she was regularly abused both physicaly and psychically, I think it is correct she finally stood up for herself. It is against the law, but imagine how long it would take if she announced it to cops. If she was not refused, it would probably take months to get rid of the man. And he would add on his insults --- Of course, the state is probably able to help her in like 3 days, but there is no certainity in that for her. And if she had to face years of humiliation from this man, it is far and justified murder from my standpoint.