I'm not sure how to handle taking the blow in a number of situations.  In the back-and-forth of an undecided conflict, does the declared action (which the opponent cannot ignore) have to take place as written if the blow is taken?

Assuming the dice say that a blow is taken...
• If the see is "I blow off his gun-hand with my sawed-off shotgun", is the player 'Brother Lefty' for the rest of the campaign?
• If the see is "Depart from her body, foul demon, and never return!", does the demon have to go?  Can it come back?
• If the see is "I shoot his horse", how do I run the rest of the pursuit confict?
• If the action would ruin a Dog's posession but they don't take 'lose posession' fallout, does the horse (or the gun, etc.) not get destroyed as a result of the action

The taker of the blow says what happens. It has to follow from the raise; it doesn't have to be the whole raise exactly as stated. "I drop the gun and shove my hurt hand under my coat," for instance. "Brother Lefty" you should leave for when you assign fallout; that's when we find out how bad it actually was.

You're the GM, right? The thing you need to be doing is following your players' lead. That means, very concretely: you give them an example or two, like I've done in the book. You let them make their own raises and sees. If there's one you absolutely can't stand, you're allowed - very gently, and without pulling rank - you're allowed to suggest some examples you'd be more comfortable with. If the player insists on the original statement, though, you're to give in gracefully.

The only time you're allowed to stand up to an insistent player is in support of another player who thinks the first player's statement is crap. NEVER on your own behalf.

-Vincent