The whole shtick of Discworld vampires is that they essentially have every power from any classic vampire work you can think of. However, they know that if people get scared of them, they can't stand up to endless mobs of torches and pitchforks. So they work on making themselves relatable and nonthreatening, by taking oaths not to drink blood, by picking up hobbies, by taking occupations like photographer or police officer, etc.
But that doesn't stop them from having a bloodlust and super strength.
So yeah, ha, that is why I am nervous about the vampires (especially since there are TWO!!!). I dropped my claim since everyone else seemed to not care, but we'll see, I guess. But if I don't wake up tomorrow, with all my blood gone, I shall be vindicated!