they seem to be addressing most of the major concerns
By possibly destroying leve failing, they kind of kill the easy thanalan SP market, now even if they have good leves in thanlan, by making a reward occur on completion, and lowering the actual in leve reward, the balancing of what is a good leve will be somewhat different. not only that, but even whether you will actually have the good leves, will matter, while thanlan may have some of the best leves, i can tell you there are leves which compete in the other zones, and definiately there are leves which are only second to the best ones of thanalan.
So people, if they dont roll the best thanalan leves will have a reason to check other towns for best sp
so now that the thanaln best sp situation may be addressed we come to the marketing, the combination of guild leves only giving guildmarks in the proper towns, and people leveling in proper towns, will increase the need for being in other towns, and thus the marketability of selling in other towns. crafters will have even more reasons to work out of other towns, and a market to get while doing it. It is a little more likely you will see more specific things in certain areas, like woodworking crap in grid, etc.
Party search is going to be improved, if in fact leve linking is no longer the ultimate SP. because people will actually party, and seek parties, people may also start seeking leves, based on what they rolled, instead of doing the same ones with the same people. The also said they would add a search for party feature, which will even further improve the party search system, which if people are using isnt even that bad.
transportation issues: this is a real factor, and i think its also why he wants to get a very basic easy and fast airship system going city to city, a no cutscene form of travel from city to city that uses money instead of anima will open up travel.
This i think will eliminate the need to unify the MW, and though it will increase shopping times for bargain hunters, I think it will make it a good balance of bargain hunting and accessibility. For easy things you probably want to stay in towns, but for expensive or important gears you may check all three.
Also unifying wards can only work if they add a delivery type system, or they make MW not transport you to other towns. Not going to argue the benefits or problems with doing that, but suffice to say i dont think they are going to be able to do that type of big change anytime soon if they did decide to do it. So lets work with what is.