If I can follow you about the wards are probably (most likely) persistant, it is false for interiors : they all have loading delay.
Wards are a far too heavy concept considering how ghost town it is. Instancied housing is lighter.
There's something crazy to see the current system with
- in-ward gardens
- houses interiors
- rooms
- appartments
- storehouse (justified to compensate the fact we can lose house but available with appartments too)
and people say extended appartements with a garden (Kugane/Crystarium concept mixed with appartments technical bases) are impossible. The excuse is just simply technically false. Almost 3/4 of flats are still open. They have the "logical"(technical) availability. People don't use them because... it is even less than a little house.
The current concept in FFXIV is the most heaviest and the less efficient system available since it's full of -concurrent- redundancies.
The only thing everyone agree is SE wants neighborood and some kind of reward feeling. But the result is full of flaws.
A ghost-town-as-a-call-for-RMT is not exactly what I call a good concept. For me, their system is just throwing the server ressources to garbage.