I would probably focus on increasing the number of apartments and their utility with a terrace/balcony that would either be a separate instance or add a room outside of the main apartment that would use special slots similar to our equipment screen for outside furnishing. And, then later make it so players could increase the size of their apartments via a quest similar to the Moogle and Ananta beast tribe's. And, then limit ward housing to FCs, and match the aesthetics to look similar to main-street and down town areas or mead halls to match the image of guilds better. I would also make wards like Mist and LB as limited single player luxuries with high requirements to unlock them.
Also, more furnishings would be less comically huge (loom>sewing machine) with necessities like normal sized bathtubs, kitchen furnishings (actual kitchen counters), toilets, sinks, bathroom floors, et cetera.
Edit: BTW, If you upgrade the Mist apartments would make the the wall opposite of the door a glass wall leading to the balcony/terrace that would have a view of the ocean and coastline.