Engi for hunters makes sense. A little off-topic: How useful are guns for a non-dwarven hunter? If bows are better anyways bullets wouldn't really help the class. I read somewhere that a certain crossbow was the best weapon because of its slow firing speed.
Also, nice ideas on the gathering professions. If you're gathering to sell you'll profit most from being able to farm effectively. However Enchanting isn't just a gathering profession, it also has a crafting side. What classes depend most on Enchantmets? Also Enchanters can make Wands, something most caster classes can utilize one way or another.
I heard Tailoring is best on a Priest (craft your own healing robes later on). Also Leatherworking on a Shaman maybe?