Which profession to level?
Your lvl 90 Pally has 2 empty profession slots, and has done some rep gains, your lvl 90 Rogue has 2 empty profession slots, your lvl 90 Priest has a spare empty slot and your Lvl 90 Warrior has BS and Mining.
I would level LW on the Rogue and maybe skinning if you don't want to buy mats. JC/Alc on the Pally and Inscription on the Priest. Finish maxing out BS/Mining on the Warrior and get one of those 90's revered with all the Pandarian races so you can speed up rep gains for the others.
When you've completed all the above, you are equipped with the necessary tools to become a "Mogul", and will have an understanding that making lots of gold is not an instant gratification pastime but actually takes time and effort and the rewards come back over time.
As for making gold with what you have, enchanting makes gold without access to the wrist/wep enchants. Identify the scrolls used by most classes that currently sell for more than mat costs.
At least grab gathering professions at level 5. (I like skin/mine). That way as you level through the game, you are grabbing thousands of ore, herb and leathers and turning that into gold in the AH at 1-2g each.
You also don't want to have to go BACK to frickin Stranglethorn Vale to spend time leveling your gathering skill. So do it enroute.
The beauty of gathering professions is their items are always easy to resell, and often more profitable than a product. Runecloth can be sold to any leveling tailor. "Runecloth Robe" has a very very limited market.
The worst of these is glyphs, so avoid inscription, or at least don't expect to make dime one off glyphs. They move extremely slowly, so all it takes is 2 or 3 competitors to turn it into a bloody undercut-fest where people undercut each other every 30 minutes. BTDT.
Engineering is of course a total money loser, enchanting is pretty rough too. Some other professions can do crazy well, but the safe/sure path is gathering profs.
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