yup. That's called proportionality.

All aggression is a moral wrong though I would pick my battles.

I agree. Don't hurt others is the basic morality. Its called NAP, non-aggression principle. All morality is based on this.

No. Some evil may occur that way. But people can be born sociopaths. Or in the case of altruism some people may actually think they are doing good. Like a war hawk who has no issue killing innocent civilians in the name of a nation.

Not always from hurt children. Some come from ideological views. For example a good deal of evil is based on good intentions. Other people are born sociopaths and cannot understand empathy.

So sad THIS is what an evil person is now, a hurt little child.