I've never cared for spray of teeth, radius too small for me, but this is a solid build for progression. Only other suggestion I may make is why not use the boar instead of bat in this build? You have nothing that uses a lot of hatred.
I was just explaining my build, but anything I said/say is pretty much my opinion and that of those I play with. Not implying anyone is wrong in their choice, just justifying mine with my own theories.
--Simply put: Mobs move around a lot. Even though 3 traps is the limit, I have to cast more for new positioning. If the mob/s are stationary, then there is only a small delay between the last Echoing Blast on the first trap before you cast a new trap. Its a small dip in DPS to start that trap over again, but Im not a min/max person to the degree that Im going to pay attention to that one blast. But essentially, this keeps my Hatred on Empty all the time.
I think the Boar pet is a nuisance and dies a lot. The benefits that you gain from having the Boar Pet out versus the additional casts on Spike Trap do not compare, in my opinion. At 550 resists, thats around 83 resist to all from Boar. A single swipe from an elite on MP5 for me averages at something like 20-35khp. I constantly see my traps exploding for 250k+. 15% Life Steal from just Shadow Power Life Steal alone and I think its easy to see why I would value just ONE additional trap cast that strikes for that amount 3 times over 83 resist all. (Not to mention, the Boar can die where the Bat Companion is cast and forget).
Hungering Arrow is debatable, but I still think Spray of Teeth is better because the odds of Devouring Arrow Piercing an additional target gets ridiculously low. Whereas a Critical Strike is almost to the point of Dependable for your average Demon Hunter.
As far as gear and stats go > Mur is right in what to work for. Though, thats going to take ages of work or a bit of Cash. Im not a fan of spending money on the RMAH though.

But it is true that about 20 bucks can save you weeks worth of grinding.