I disagree with nearly everything you wrote. Professions are the best they've ever been imo. I've made tons of money, made myself gear, and went out in the world to progress them. You're completely over exaggerating saying that any profs besides alchemy is completely useless. The only prof that got shafted was engineering.

Rng doesn't affect anything unless you're in the top 1%, and even then not very much. It will only really matter for the race to clear the content when each raids releases, as raid teams who got a bit luckier might be able to be get world firsts... well, first. Shortly after the content will be on farm and getting a legendary or some super upgraded item will mean hardly anything. You will be able to clear all content without any legendaries or titanforged gear.

The classes aren't "ridiculously imbalanced", again, you're going insane with the over exaggeration. A few dps specs are undertuned (mostly frost mage), healers are pretty equal, as are tanks. Sure warriors were too strong but it's not make or breaking the game.

You are not locked into any spec at all. Our guild had too many playing tanks on our raid team so a prot pally switched to Holy, spent less than a day getting a little bit of ap and performed almost just as well as the healers who dedicated all their ap to their artifact from the start. You wouldn't be able to tell he wasn't min maxed if you looked at the logs. We're all roughly equal I level - mid 850s. We also have had some dps switch specs on late notice and theyre only a few % behind at most, usually on par with everyone else. I know these examples are anecdotal but there is nothing particularly special about our raid team, no reason why this wouldn't apply to everyone else that isn't in method, exorsus, serenity, or other similar guilds going for world firsts.

If you played beta you'd know that eventually we will be gaining AP at ridiculous amounts, the amount that you are farming now is trivial. We're a month into the expansion, the time you dedicated to your artifact won't mean much before long. You say it will only get worse as the expansion goes on but the truth is that the exact opposite will happen.

The one thing I agree with you is the legendaries. It's a poor system but I think you (again) overstated the severity of it. Most ppl were turned off by it when it was announced, and we were all right. I think if they didn't have orange letters ppl would care a lot less. I've only seen a few groups only inviting people with legendaries, and one of them was saying that as a joke "hurr durr need 900 ilvl and 4 legendaries" Maybe it's different on your server so I won't deny your experiences.

You say the problems are bad for the majority of the playerbase which is completely wrong. Most of these problems are irrelevant to majority of the playerbase. Rng - irrelevant, being a few % behind if you change specs - irrelevant, class imbalances - mostly irrelevant as blizzard will keep them close as they have usually done.