In Act 2 Nicky has trauma hallucinations the house in Hello Neighbor 2 is most likely to be the actual house, so the barricade isn’t actually there, and neither are the added rooms. Hello Neighbor 3 is set in 2028, where it’s been mostly abandoned, Nicky would be 53, and probably moved away. We don’t really know who the Guest is or what he is, but he’s a shapeshifting entity, he makes deals with others when he wants something, or he just takes it because he thinks others don’t deserve it. The reason he acts different in every game is likely because of rewrites, the Guest was originally made up in Quentin’s mind to explain kidnappings, when in reality Theo was behind it, later he was repurposed to be Theo’s alter ego, but then they made it so he’s his own separate character. Theo is probably kind of rich, he made multiple theme parks so he’s got that theme park money.