Logical to assume, yes. There's reason to assume a lot of things. The likeliness of it though is what matters. From that quote, you cant really assume there will be that kind of mission because it uses the word protect, not rescue.
No it says:
Guard your home from unwanted visitors like marauding kidnappersIf you fail to guard your home, there "has" to be some sort of repercussion for that, which would likely be a family getting kidnapped since there kidnappers not bandits.
Vampires attack cities during the night if they have not its a bug.
I have had few vampire attacks, never heard any NPC talking about getting blood svcked or whatever. If it does though, it's irrelevant... it's to set the mood of the vampire theme, there not programmed to do this. There are kidnapper quest in the game though.