I really like looking through decorations and trying to make a cozy space in housing with this, but would love it even more if they could improve on things.

First of all, things that should be doable currently:
-Higher outdoor deco limits, even just 10 or 20 more each.
-Higher indoor deco limits, especially for things like mansions so they're not all empty space.
-Workshops for FCs accessible without a house like the GC Barracks that you can just click on from a set location.
-Allow tenants to apartments so I don't have to have it open to everyone or no one, or at the very least have a friends list only option.
-An option to make food decos inedible please, I'm paranoid about new people eating limited event items I got for the FC house.

And slightly more ambitious things:
-Expanded apartments: Like others have mentioned, the ability to purchase/upgrade to a bigger apartment. allow an outdoor space for gardening and outdoor decos etc. And allow FCs to purchase them too. Make them an appealing alternative to a house.
-The ability to float items and move them more freely without needing to use a glitch.
-And more flexibility with clipping into walls/pillars, it's annoying when I want to put something flat against a wall and can't because of a pillar.
-Allow anything placeable on the floor to also be placed on a loft, and maybe a way to float/detatch the camera for easier decorating of said lofts.
-A checkbox on items, similar to how you see if something is dyed, that allows us to control whether it is interactive or not. So we can turn it off on walls we've put wallpaper on or food we don't want eaten etc.
-1 wallpaper to apply to more than one wall partition at a time.

That's about all I can think of for now.