Jim doesn't know how his counterpart dies - how he dies, for all the two of them know just yet - but he knows what it was like for Ambassador Spock. He felt it in his head, and heart, like it was his own memory.

"Oh, man." That's great, about Q being mortal. A hilarious thought, even though Jim's sure he'd be just as obnoxious even without the powers. And then he shrugs, because-- "I'll use any tool at my disposal, at any time. And Q's certainly a tool."

The ego that Jim Kirk is supposed to have is present, sure, it's in no way a myth. But part of his effectiveness is his ability to delegate like a motherfucker, and he'll put everybody and anybody to work, ensign or fifth dimensional superpowered being.