"There is very little liability in only shooting people who need to be shot."
Probably one of the stupidest comments I have ever seen. As a citizen, legally licensed to carry or not, if you blow someone away, you will be in trouble. And YOU don't get to make the decision that the person "needed to be shot."
Except in your own house (and maybe even then) if you shoot someone, even if not fatally, you WILL be arrested. You may have to make bail to get out. A DA WILL decide whether to prosecute, and that decision may have more to do with the DA's political ambitions than the merits of your case. Then, IF you are acquitted or not prosecuted on criminal charges, the victim's family (who hated his guts) will sue because you killed their "adorable" son/husband/father.
That is why you better not shoot anyone unless you have absolutlely no choice. And why ANYONE who carries a gun should have an attorney on retainer and consult with him/her in advance on what to do if you do wound or kill an attacker.
(FWIW, bragging about your expanding bullet handloads and the hair trigger you put on your gun and how you have always wanted to shoot somebody are not good topics of conversation with the cops.)
Oh, and buy as much personal liability insurance as you possibly can, and make sure it will be good if you are involved in a shooting away from home.
Jim