My preference is for everything thats purely functional for a house should be put into a room in the same way the airships were put into a workshop.

Gardens should go in a greenhouse room.
Stables should go in a larger stable room (like you'd see at a horse farm).
Aetherial wheel stands should go in the workshop.
Aetherytes and mailboxes should be included as a part of the house and not a separate item.

The extra room door should be made available to all houses regardless if they're FC or not. Building airships solo sucks but if someone wants to put in the effort, let them; and while I enjoy the stupidly overpriced airship mats I get to sell, the market could use some more supply.

And if we really want to get crazy, lets have some glam options for the workshop (and other rooms). If we can build exteriors for our houses, why not interiors for it? or let us change the walls/floors/lighting like we can with the house itself.