Ok
Now I got all endings, but still don't understand - who's mister Bob? What's his connection with Alesa? And a lot more:>
When you watch the video tape, little Alesa says: "I want a new family, I want a new house". Mr. Bob was the one who recorded that video and wanted to grant Alesa her wish: a new house/family for Alesa.
I would say he's a demonic entity with limited reality warping powers who is obssesed with Alesa. His ultimate goal seems to be to turn Alesa into an amorphous blob and be with her forever...or at least until he gets bored of her and looks for another victim.
The inside of the house is actually in a different plane, that's why the police can't find anything.
I'm not sure myself though. And Mr. Bob might return in some of my next projects, who knows...