arcane help?

Which talent tree should I be using, one with Arcane Barrage or not?
Also I see that almost everyone is switching to fire at a certain point is it that much superior to arcane and will I be discriminated against when playing it?
and I have engineer as a profession do I use the standard enchants for gloves and boots or hyperspeed accelerators and Nitro Boost?

AB is optional. I like it. You can move 1 point from Student of Mind (+% spirit) to AB. 3% spirit isn't a lot of spirit especially if you've got no spirit parts like you shouldn't anyway.
At BIS it should be better, but I've seen arcane mage do really well in end game I doubt anyone would turn you down. You'll be arcane for a long time, until you can get a lot of crit.
Use the engineering gloves enchant because haste is awesome for arcane. Use the boots from engineering if you don't need extra hit from the other enchant.

One nice advantage arcane has is that you can pick up 6% hit from talents, that helps a lot while gearing where hit may be an issue.

thank you.

I'd go with barrage, why? Sometimes RNG is just bad, and you don't want be casting arcane blast 3+ times at 4 stacks at lower gear levels.
It's good instant cast to have while you have to move.