I think you have to talk to the fairy maid to be able to enter your house again after upgrading.
Correct me if I'm wrong but you seem to get EP from sex scenes with enemies. In other words losing and staying at bosses gives you easy moneyyy. One nice way to wait for your house to finish upgrading is "collecting" EP at bosses.
Anyone figured how to get scenes involving the NPCs yet? Also does anyone have any idea where the fairy maid is at a specific time of day. Sometimes I can't find her in the succubus' house or outside watering the flowers in front of the house. Does she go somewhere else occasionally?
Also when talking to the succubus what are the 2nd and 3rd option?
Not sure when exactly, but one of the places the fairy disappears to is the empty campfire circle southeast, east from town. I've only seen her there once though, and she left after talking to her there.
As for 2nd and 3rd option of succubus, 2nd option increases enemy strength, 3rd option decreases it. You have to pay ep to decrease it though.