I think Yoshua might have to revise his post a bit before anyone else posts with what Jack's said about the realism of saying the rather long incantations perfectly in less than handful of seconds (or some kind of cascading failure of scene integrity might occur). 

As for Merc's questions, though:
	1.) Yes, vampires do have souls. 
	2.) ...Blessed? What do you mean by "blessed" - as in containing divine energy more specifically? To that, the answer would be "no," as far as I'm aware. They do contain magical energy of some description, though, so yes, they are magic-imbued.