If you are going PvP BG'sthen I would ditch the palas/druid and put 2 more Hunters in.
1xMM and 4BM is good,you could spec for Surv for Expose Weakness,but I found losing BW&TBW on 2 toons was more than I could handle.
Hunters defense is mostly tracking,hitting hard,stealth detection and getting out,players will always be looking to skirt your range and get into the middle of your pack and destroy,whether thats Fear,Blink/ABlast or at the moment Retripalas/Warrior AoE/
Another trick is to peel off your pets and kill them so speccing BM is a real help here.
To sum up your pet is the most important thing for fending off close too rushes BW,TBW and Trinkets will save you far more than ranged DPS will,plus the extra 2 toons DPS stacks up well.
Your Palas and Druid will work nicely in instances keep your pets alive so completely possible.
Regarding healing in BG's Hunters are always a prime target for Warriors and Paladins and I just couldn't find the time to run a healer and coordinate tactics without leaving myself open to more attacks.
I found it easier to just die and res,as it saves time and mana,esp for reviving my pets.
Arenas I gave up other than strugling for gear,once they figure out your a multibox hunter strong team they just LOS you heal/and CC your pets picking off your team.
I wish you GL its real fun and for AV truly evil .