Wow, a lot of really great ideas here. Its a shame something like this wasn't started on back in 3.0 when airships were implemented. It could have started out with a few of these features and gradually evolved overtime.

I like the idea of everyone getting an airship through the story, and being able to upgrade it as they see fit throughout the game. It would really be the lasting content that this game so desperately needs. The FC portion of this seems like a good way to actually give FC's something to work towards as a group.

Lastly, I think the housing idea is genius. Literally the perfect way to implement personal housing, have it in your airship.

The only drawback I see is the technical implementation. Not only will the new airship content have to be added, but maps will have to be redesigned to accommodate them. But hey, we can dream~~