Digging the book store, it's nice and simple, leaves room to hide puzzles/treasure.
Ingo's Emporium also, meets our needs, glad to be able to cross it off.
Sebastian's house too, done, I agree.
As for the apartments, I don't know about Gloo-Tan. He'd make more sense for us to put at a restaurant or grocery store, which would leave his house empty. My personal philosophy is if you're gonna build a space intentionally for a purpose (ie, this guy's apartment), you should make sure it's used for that purpose. The conflict is, we've got a grocery store which needs customers, and houses which need residents. If we have the same NPCs for both spaces, we'll stretch them thin and have emptier towns.
That's way overexplaining, haha, sorry. Basically, a different NPC besides Gloo-Tan might fit better, like Forsithia. But also, this is your game as much as mine (community!), so if you think it'd be better differently, that's your prerogative and go for it.
Anyway, side note, can we have a door/ladder to the attic in one apartment, and than have an entrance to the roofs from the attic? I think it'd be a good way to get up there.