... Throughout the whole discussion I was wondering on how you actually plan to punish "normal" criminals. You said that murderers should be sentenced to death along with rapists and other rotten scum at the bottom of society. But what do you want to do with e.g. thieves or liars? In some way it sound like you want to reestablish the punishment system they used in the middle ages ... people who intentional lie get their tongue cut out? People who steal get their hands chopped off? Well in this case you don't need prisons anymore as those people cannot commit the same crime again. But despite all that, you must first of all define what IS a crime and what is not!
For example ... is a soldier a murderer as he intentionally shoots other people?
Or is a 12 year old boy who steals because he needs food really somebody who should be sentenced for that? In my opinion murder, rape, child molesting are crimes in any case and should be punished. But sentencing such people to death first of all is only a form of revenge for family members and/or other people. But isn't a person who sentences a murderer to death just a murderer aswell? Isn't somebody who orders people to kill a criminal just as bad as the criminal himself? I totally agree to you that those people must never be set free, but killing them is definetly not a good idea. But you could set up new punishments to prevent such crimes.E.g. you could castrate every rapist. Yes I know that this also sounds very harsh, but maybe afterwards you could even let those people go back to society, as they now cannot rape anymore. But concerning those "small" criminals like thieves, liars etc. I think probably the best idea would be just to punish them with fines.