But...Gulum -Ei said the house was mine....I'm so confused...
He does? I must've missed that part. I'm not sure how he can give it to the player, though, when it was apparently already sold to someone else.
Killing Aringoth is also completely optional, IIRC, as is the killing of anyone else on the estate. So the place was never intended to be emptied out as a matter of course, I think the way the bill of sale is worded it seems like the place had been sold and Aringoth was just staying on as a tenant to run it, it's only vacated if you choose (or are forced) to kill everyone there.
Edit: All the beds are mine too. The wiki says the chests are safe, so I think it was intended to be a home...
I'm pretty sure I've killed bandits in their hideouts and then slept in their bedrolls, I think it's commonplace for property of those you kill to be made available to you, if only because the person who owned it is now dead. That doesn't mean you own the surroundings in the same way you own Breezehome or Vlindrel Hall after purchasing them.
I don't know, I guess you could try living there and see what happens. There's some discussion on the wiki page about whether or not containers respawn but no definitve answer from anyone who's tried it. I would hate to come home though and have to fight my way through a bunch of hostile respawned mercs just to get in the place and check to see if my stuff is still there.
