It sounds like a dream. Account-wide professions. It sounds too good to be true. All those blacksmithing and jewelcrafting recipes I collected in banks of my alts over the years, could finally be put to use. Well, not really jewelcrafting, but it is nice to have all the recipes in the book. Without any pesky level requirements limiting me to first level the alt, so I can level up the profession.
Account-wide professions would make my life easier. I could make my own Living Steel bars needed for my engineering mounts in making. I could make Arcanite bars in numbers that would make Al'Akir turn in his grave as I finish the Thunderfury. I could finally use all those blacksmithing weapons that my Alliance warrior has, for my Blood Elf paladin and death knight. And then on another two warriors, and a paladin. I could finally make use of Felsteel Blade recipe that just sits in my bank while I try to obtain that blade from other blacksmiths.
But besides the positive effects this would have for an individual as described above, what are the down sides? Can it really be all good without bad? How about in-game economy? Well, trading and auction houses would be first to take a blow. If you can make everything by yourself, in most cases you will. This would lead to stagnation in trading that is clearly visible on less populated realms.
And with less trading, comes less competition. Since most of players can now make everything on their own, those few who still produce for the market, find themselves in a monopole of sorts. They can elevate the prices to their liking. Because in most cases, the buyers will either cave-in and buy, or find another, more reasonable offer. But as to the real capitalism where competition is strong, and pushing the prices down, here, when there is no competition, there is no reason to lower the prices.
We would end up with most of the profession trade goods quite expensive. Yet on other hand. Anyone who would invest enough time into leveling the professions they had need of on regular basis would be fine. Those individuals would not be affected by this sudden change in economy.
Account-wide professions would be a godsend for emptier realms. It keeps those greedy at bay as it hurts their profit directly. Since most of the players could now make their own things, they are forced to lower the prices if they wish to sell anything.
It would make matters easier for many that play on less populated realms. And with more people just accumulating the gold, and not spending it, I might actually have a chance at the black market auction house. Seeing Dreadnaught Pauldrons sold in a matter of day for 105 thousand gold is just wrong. I would like to be the one who throws that preposterous amount of gold at black market to get those pauldrons.
But maybe, just maybe all professions account-wide are too much. I think five would be nice limit. And you can choose which five professions are available account-wide to each of your characters. For example, my paladin has mining and engineering. What that means, is that he can choose three more professions to have access to, but did not level up. If I choose blacksmithing, jewlcrafting, and alchemy, I can make use of those professions even though my paladin never leveled them up.
As long as at least one character on my account has them leveled up. That means, if I have blacksmithing maxed on the alt, everything is available. I can teach my alt all the recipes, that would otherwise stay in my bank. If my alts' alchemy is 376 (I wish), my main can use all the recipes up to 375. And if my alt's jewelcrafting is 96, well, not much use for my main. You get the idea.
This would give a player enough manoeuvring space to make the most of it, while still leaving some space for market. If anything, gathering professions would become very lucrative business.
All in all, the upsides of individual are greater than the downside of majority. To a degree, maybe because every member of majority is an individual as well. As far as I am concerned, account-wide professions are go.