Alchemy is by far the easiest crafting trade skill to level. Whether or not alchemy is useful to you is a different story.

As was said, you don't need primal might for too many things, but you'll likely need a few depending on the professions you decide on. Don't take alchemy just for getting primal mights. It does have some cooldowns that might be able to make you money, but if you want them you can just power level alchemy when you get to 50.

Mining is the best money maker of the gathering professions but is also the hardest to level. Skinning is easy and usually sells reliably in my experience, while herbalism is in the middle on all sides.