All those are valid questions. But I can ask the same ones about True Hope, or True Courage, or even True Love. The answers will likely vary between GMs and should absolutely be delved into if you're playing such a creature...but asking them doesn't invalidate the idea of the emotion and Catch in question.
Also, in order:
Alot? All you reall need is one. It's supposed to be a rare Catch after all (+0, remember?).
The same could be said of True Love or any of the other emotions. The GM is needed to find an appropriate balance.
Probably vulnerable, unless he's got true, real, faith in something larger than himself (Murphy's belief in the law likely qualifies).
Is there a meaningful, non-semantic, distinction?