As an FO, I really couldn't care less what time we block out, or board the aircraft. Yeah, I'd like to get the extra sleep if it's early and the van is only on the hour and we sit at the gate forever...
And I really hate coming back up from the walk-around to stand in line with the pax to get back on board. More than once I've found something on the walk-around that ended up cancelling the flight. (Like a bent standby pitot tube. Thanks, DTW Mesaba gate agents.) To summarize: LET ME FINISH MY ******* BEFORE YOU BOARD otherwise you may have to pull everybody off...
Return to topic: But if the gate agent can't let us down, what can we do? Nothing.
Anyway, "Put the late on me if it makes you feel better," is what I tell them if it comes to that. I have a real hard time lately giving a ******* about anything but safety and going home.