I made a suggestion earlier about adding 3 types of apartments... basically the loft..
Then a 2 story apartment (slightly bigger then a small house) and a 3 story apartment (slightly bigger then a medium house)
But if I find the "upgrading with gil" part interesting... hopefully they'll finally allow us to use that damn balcony door to go in & out of the house! xD

As for allowing your own alts in the house... I believe the system should auto detect your account and make it autoshared with all your alts without having to change settings or invite your own alt.

Also while you guys and girls were replying I added another suggestion about adding workshops to apartments which is one of the main reasons why there are so many one man FC's out there.