I'm about to tear down my hunter and go with the best profession/race combo on the Horde side. I assume it's Panda with Engineering and JC. Is that accurate? I use to have a spreadsheet back in Cata, but I assume that's obsolete.
engi/LW is strong combo. Orc for BM, panda is good too, troll 3rd. Nothing gamebreakingly better about any of these....
For professions, eng and LW are the winners. The reason LW is great is because of the long-forgotten (by 99% of the population anyways) Drums of Speed. Anyone that says something else is wrong, the answer is eng/lw.
As for dps, I believe orc is best all-around atm by quite a bit (definitely number one for BM), not panda. If you really want to min/max you would want to go BM as well for single target/SV for multi-target, otherwise you aren't min/maxing and I don't see the point in you wanting to min/max without min/maxing.
It can be a pain in the ass to target, but cobalt frag is nice. Very nice. Even on single target it's worth it, but add in adds, it really shines. Also synapse springs are way better than other static buffs since we can control when we get it. It's great when it syncs up with BW/amoc.
Forget the frag on the belt get the rocket boots instead. The tiny dps boost the frag gives you is far less then the ability to get out of bad stuff fast. More raids die due to mechanics then from not enough dps. Engineer/ JC is the best combo imo. 320 x2 gems is good but mathematically all crafting professions equal to about the same dps boost so its really your choice. Engineering has the most utility when it comes to raiding with asborbs, speed boost's and the glider.
going to agree with crooklyn. good play from a smart player will outweigh the use of the rocket belt of the free damage from the frag bomb. posthaste solves most if not all mobility issues that can happen. the duration of the nike you get from it is more than enough to get you out of bad things.