Re: Did Spock ever kill anything?
We don't know for sure, but Spock may have killed an Eminian guard or two during the mission to rescue Kirk at the council chambers in A Taste of Armageddon
Weird that Ambassador Fox wasn't more concerned about what became of his aide at the end of that episode.
Check the circuit!
Mr. Spock, The Cage
(The very first line of dialogue in the series)