So in the Dresden Files RPG, one can spend a fate point, invoke an aspect, and make a declaration. I'm having trouble coming up with a reasonable set of guidelines as to the scale and scope of declarations that can be made. For example:
Phil is an investigator. He has an aspect,
Memory like a Camera. He sees some ancient writing on an artifact, and he'd like to identify it. Rather than rolling Lore, he spends a fate point and declares that "I have a
Memory Like a Camera; I've seen this writing before and therefore know its source/text".
Bill is in a fistfight. He uses a maneuver to place an aspect
Off Balanceon a thug. In the next exchange, he tags that aspect and declares "The Thug is
Off Balance, so he falls and I run away safely."
Johnny is in a gun battle with an evil vampire of doom. He knows that the Vampire has an aspect
Vulnerable to Fire. He spends a fate point to declare that the forest they are fighting in is full of dry kindling. He then spends another fate point to declare that the forest has caught fire, and then another fate point to compel the vampire to flee, confronted by this fire.
Fred is in a confrontation with the bartender. He deduces that the bartender has an aspect like
Runs at the first sign of physical danger. He brandishes a knife, and spends a fate point to compel the bartender to immediately back down and yield.
I'm having trouble figuring out if these are reasonable usages, too far, or even not far enough? What are the standard guidelines for usage of fate points/aspects/declarations in these contexts?