As everyone has noticed by now, the Market Wards in Ul'dah for many/most servers quickly fills to capacity. The chances of getting into the correct Ward are worse than getting into any Ward at all.
For all intents and purposes, the Market Wards are pretty much an Auction House as is, with the exceptions that 1) every time you make a purchase you're kicked all the way out of the menu and 2) the menus to navigate to the item you want are... terrible.
The UI for the XI Auction House remain superior to XIV. I just want to open up the "AH", look for a specific slot (like legs, or body), and then happily sort by alpha, or level, or class, rather than hunt by Ward, which can get annoying in a hurry.
Part of the reason why the server load is higher in Ul'dah is because everyone goes there to sell things. Why? Because it's a centralized location. So, the first step to fixing this would be to link the "Auction House" across all 3 cities. Put something up for sale in Gridania? People in Ul'dah or Limsa can buy it. This right here will encourage the folks who don't particularly like Ul'dah to stop hanging out there (like myself). Believe me when I say it has nothing to do with the inn, though it's very annoying when I'm doing Goldsmith LQs and have to fly to another city to log out for the day.
And, yeah. I'm fine with keeping it so that only the items on bazaar on your retainers are up for sale, but abolish the Market Wards as is. Maybe make it an instance like the inn room. A small Auction House counter room where you can set up your retainer and call it good. While you're at it, please make that area less hideous. I've always hated how the Market Wards are set up. It's just this ugly claustrophobic INDOOR tunnel filled with stupid retainers facing each and every way. Ugh. Or, you know, just make Auction House counters where you call your retainer like the bell, but they are then sent "somewhere" to go sell your stuff. Or whatever.
Let's just not pretend that people enjoy going INTO the Market Wards, or being ejected from the menus every time they purchase something from the entrance.
So, how about it? Understandably, this won't completely correct the problem of too many people hanging out in Ul'dah, but it will go a lot farther than closing the inn for long periods of time.