Even those who believe this acknowledge that many of the commandments are repeated, either in word or in idea, in the New Testament. Debates continue today about whether an image of Jesus is an idol, or whether the Sabbath commandment is repeated in any fashion, but "thou shalt not kill" is directly restated in the text, and emphasis added on heart motive as well. (In other words, Jesus calls people out who use harsh words but don't stab people as violators of the commandment.)

In any case, the word means murder, not any killing. This is plainly true in that soldiers are not immediately called to abandon their posts.

Sure, but, from a Biblical legalistic point of view, then the appropriate New Testament passage should be cited.

I've heard conflicting stories about this. Sometimes it is phrased as delivering us from the vengeful god of the OT, other times it just embraces and extends.

I'd love to hear something official just to know how best to criticize the hypocrites...