Tell that to Catholics, whose Sixth Commandment reads "You Shall Not Kill."

No problem, as Catholics aren't the authority on the Bible. Even the Jews (who predate the Catholics) have it as murder which I think would be more important than the Catholics taking an improper translation of the original language. Not only that, but the Catholics then used  Catechisms to note which types of kills are ok, and which aren't. If the correct translation was kill, then we would have immediate problems with the Bible due to God instructing his people to put murders to death which would be against the 6th commandment.

There are a lot of things that I believe the Catholics have messed up, but this is neither the time nor place to address those issues. If you wanted a specific and improper interpretation of the 10 commandments you should have asked of it.

Especially in the case of religious texts, the author's intent needs to be taken into acount when translation occurs. As you said, the best translation here is murder rather than kill. One problem with a direct, literal translation is that langauge is not static. The meaning of words often change over time, so texts need constant revision if they are to be understood. If I had to venture  a guess, I would say the usage of the word kill had to do with the limitations of language rather than the word corresponding to today's usage.

Obviously that would be insane and locking people up is in no way the same as executing them. The emphasis in modern society is rehabilitation and if they cannot be rehabilitated to protect society. Protecting society does not have to be "kill the bastard".

Maybe you also agree with stoning women and lobbing peoples hands off for stealing sweets, where does your version of justice end when is it a good time to sanction state authorised killing? At some point we and in we I would general refer to what is known as the west tend to frown on executions. Very few western countries execute the US is a very notable exception and one that I think makes it difficult for it take the high moral ground at times.