I think, as far as battlegrounds are concerned, enhance is still very much a supportt character.
Find your Shamanism buddy and just sidekick them. Your utility is amazing for allowing other classes to shine.
You can purge which only other melee DH can do. You can AoE or single target snare at range, which is huge for controlling the fight zone and helping other melee stay sticky without needing to spam their snares. You have the luxury of a ranged toolkit, which means in the heat of battle you can place that cap behind a hard casting healer and catch a stun (bg only) or land that hex while they are trying to deal with your windwalker/ret/boomkins rolling them.
You have the shortest interupt and grounding totem, which can negate lots of good spells and keep people up.
You provide extra attacks to other melee, which turns into resource for certain classes. You offer a free HoT that can heal multiple people. You have powerful offheals that are instant and can bring an ally back from death.
To top this off, you have some of the strongest burst at range allowing you to chase well or kite well.
Be bait. Enh are known to be squishy…so use that and lure enemies into bad position and crap on them with your team. That rogue will be sad when you pop out of his stun and chain harvest him for 25k and heal yourself and allies the same amount as he woefully realizes he shadowstepped you into the middle of your team while you were ghost wolfing.
Peel for your healers with your range snares/cc. And enh can easily go from frost shocking someone off their healer, to instant healing someone else 40 yd in the other direction, to grounding a chaos bolt, interupting a convoke, purging a dps cd/buff/hot, and then nuking down someone 40 yd in other direction with ascendance/doom winds. This is a lot of impact on a battle.
The main issue I feel with enh is not enough gcds to use purge, unlike Ele who can really maximize it.
But to me. Being a sidekick to other mdps is one of the more satisfying ways to play for bgs.
In arena, your job is to just blow someone up as fast as possible during cc chain.