The problem is that your moral absolutes are, in practice, a kind of moral relativism.
We (and I'll include all of us here) interpret these things according to our convenience. Now, if the commandment says, "Thou shalt not kill", I will assume that is what it means. Now, let's suppose, that no one kills i.e. not criminals, or murderers, citizens, police or soldiers of any kind....that would be a good thing, in my opinion. However, we always say, "You did it first so I am justified." Another excuse is "God is on our side" so therefore we are justified or "I am good and you are evil". Personally, as much as I support our troops, I cannot go so far as to claim that the god of this vast universe is on our side as comforting as that may be.
Ironically, since I am less of a literalist than many of you, I believe that the commandment means what it says. However, we (and I must regrettably include myself) are not willing to live by it.
It therefore would not apply to capital punishment as that is clearly permitted by Mosaic Law; nor does it apply to just war because in war the objective is to defeat an enemy, not kill the individual combatants.
However, both euthanasia and abortion (assuming you believe that life begins at conception) are deliberate acts of murder.
Here is an interesting editorial on the subject written by a rabbi:
(I pinged Zionist Conspirator because his knowledge of Hebrew and the Torah is far superior to mine.)