Yeah, I'd much prefer we go back to the Morrowind/New Vegas treatment of NPCs where anyone is fair game for murder, but such a system wouldn't mix with such random encounters, by the sounds of it.
Personally I hate every single [censored] NPC in Skyrim (no I'm not kidding) and wouldn't mind losing a stupid misc radiant quest if it meant never having to mean their repetitive dialog again, but if they would just stop marking everyone and their mother, I could do the job myself. Vampire Lords? I don't need them to kill NPCs for me. Vampire Lords just sound tedious and repetitive....which, is the very reason I want the NPCs to die: because they're repetitive.
And as you said, it's not player choice if characters dying is a dice roll beyond their control, requiring players to obsessively use the Slow Time shout and scout the ENTIRE town upon leaving and before exiting, all in the name of saving their beloved NPCs...
Having said that though, while I agree they should scrap this random encounter, the DLC has already been released. Name one DLC that's ever been patched since FO3/Steam/PS3 Network.
Exactly... :/