Spock this, Spock that, it's always Spock. Spock died to save the Enterprise from the Genesis Device detonation, then was ressurected by the same wave. Big deal. Kirk died at least once in Vulcan and another time in the Romulan vessel (both times by the hands of Spock, btw). AND came back frm the dead. Was there any other occasions of Kirk dying? There are too many episodes to research alone
He wasn't dead in either case. Both times, McCoy used drugs to make him appear dead. Oh wait. On the Romulan ship, Spock simply used a pressure hold to simulate death.
Unless I'm mistaken it's only once, sure in the examples above MCCoy declared him dead but that was simulated. Now Daniel Jackson from another well known franchise can give lessons on (not) being dead. So much so it became a running gag.
Dead enough for the Vulcans and Romulans. Is cordrazine that much different from the genesis wave or nanoprobes? I mean, in a fantasy/sci-fi way?
In space, no one issues death certificates. (Except McCoy. When he says "he's dead, Jim", then he's dead)