So Belethor was slain by vampires while I was away and Isolde took up his store as her own. What happens if she gets killed as well? Will the game generate a random NPC to take over a store if no one is left to do so?

Thanks in advance!

Interesting question!

I'm also eager to hear the answer to this, as I've yet to play any of the DLC despite purchasing them as soon as they arrived on the PlayStation Store!

I seem to remember the Skyrim forums having a Dawnguard, Hearthfire and Dragoborn section but I've been away from this place for such a long time they must have taken them down, or merged them all into the main one idk. Shame really, because I remember seeing a thread giving advice to players worried about the threat of Vampire attacks in the cities and how not to lose any NPCs. I don't want Solitude or Whiterun turning into 'Ghost Towns' once I begin playing Dawnguard! >.<

If both are killed then the store just won't open anymore and will always be locked. You could still break in I think, but no one will be there.