I'm not insulting anyone, least of all because they don't agree with me. Their opinion is a result of ignorance and the emotions they feel that hinder rational thinking. This isn't an insult, it's merely stating the obvious. And frankly, if you're going to accuse me of insulting someone as if doing so is some kind of wrongful act, then maybe you shouldn't insult me in the process. It hurts your credibility, and basically renders your words meaningless.
You seek the death of other people because they have committed certain acts. One can define punishment as "a penalty imposed for wrongdoing". So yes, according to this definition, you seek to punish, because when you think about someone raping a hundred people, you get mad, you feel certain things, and thus you are let yourself believe that other people should die because you experience these fleeting feelings. And as a result of this, you sink to the level of murderers, making the only difference between you and them the fact that they murder themselves, while you would have the criminal justice system commit your murders for you.
Countries with capital punishment very often have more violent crime than those who don't. Like I've said before, all it does is fulfill the wish you and people with the same opinion as you have to see other people killed. It doesn't decrease violent crime and is useless in such a regard.