Well, if the shooter has absolutely no loss of utility done to him by the act of shooting, what'd be the point of warning the other guy in the first place? He'd just let him approach and then shoot him.

I am not sure if this counts as an argument per se, but several works of fiction have had instances where a time machine moves a small amount into the future, (say 1 second), and always travels to 1 second ahead of the protagonist, and thus is invisible. Wouldn't this just give the protagonist a 1 second head start against the villain?

At a time of t=5, both would be visible and present, but the protagonist would have 5 seconds of action time, but the "clever" villain would only have had 4 seconds.

I have wondered a similar thing about the real-life efficacy of bribery.

Yes. For some reason, I consistently add an "er."

Edit: as I understand The Strategy of Conflict, a threat is a conditional promise which will make the both parties worse off, if carried out.