Training help you much in doing “pulling the trigger” without too much thinking. It is not giving you super powers but it help you, and when the moment come everything counts.

Could you live with yourself knowing you’d ended another person’s life?

Sure, most people could live with that, but if you talk about quality of that life that is the other thing.
Sooner or later it becomes something that you need to cope with, think about it, dream about it. Then you gonna look for techniques for living with fact that you took other people lives etc.

Some people accept it better, some not, simply it is not normal to take other man life, even if it is justified. So, man need time to solve some things in head.

From the experience, do not think that if you take someone s life, it is gonna be much easier later because it was justified.

Yes, it can be bring to the point of the doing like you are “taking out trash” , i know that, but expect to be in problems later because that, you gonna pay emotionally for that, even years later.

Of course all this do not mean that you need to “pacifist” if someone put your life in danger.
Simply some things need to be done when times came, and simply some things need to be paid for.