In terms of a command trait, I was thinking more along the lines of a level of authority when organising a crew or getting a ship prepped for launch. So for example a command officer has ultimate authority, but XOs and Lt. Commanders have a high enough level to go ahead and launch a ship if they deem it necessary. On the otherhand, command authorisation for an ensign would be very low.
I think we need to avoid that in the forums though as that is what actually goes on in the shift (though potentially we could have it as some kind of combat element between shifts, we need to consider how it impacts the game and actual missions though)