As to whether you have to drink the vampire's blood, that depends on whether you're going by Hollywood (usually) or folklore (not usually). The answer here is no. As far as what the vampires are going to eat - that is the eternal question. I sort of envisioned this becoming a Daybreakers-esque scenario where the remaining humans are farmed for their blood. Or maybe vampires can live on each other. Either way, if there's a way to survive, Arthur and Eames will find it.
Re: This is brilliant!
As to whether you have to drink the vampire's blood, that depends on whether you're going by Hollywood (usually) or folklore (not usually). The answer here is no. As far as what the vampires are going to eat - that is the eternal question. I sort of envisioned this becoming a Daybreakers-esque scenario where the remaining humans are farmed for their blood. Or maybe vampires can live on each other. Either way, if there's a way to survive, Arthur and Eames will find it.