[HaZeust]

Even 1 (do not murder) is shaky.

Not saying it's good, but if you put people through a rudimentary hypothetical or prior history example where killing someone (i.e. Hitler) would be justified as what essentially comes down to a no-brainer Kaldor–Hicks efficiency (net benefits / potential compensation), A LOT of people will agree with you. Is that objective or a moral absolute?

[pc86]

Does traveling through time to kill Hitler constitute murder though? If you kill him in 1943 I think most people would say it's not, the crimes that already been committed that make his death justifiable. What's the difference if you know what's going to happen and just do it when he's in high school? Or putting him in a unit in WW1 so he's killed in battle?

I think most people who have spent time with this particular thought experiment conclude that if you are killing Hitler with complete knowledge of what he will do in the future, it's not murder.