As much as I love Ret right now, it’s no secret that its busted. As far as damage, I think the main talents/abilities in need of tuning are: Justicars’ Vengeance bonus damage on stun, Inquisitor’s Ire, Vanguard of Justice, and Divine Arbiter. For JV, 25% bonus damage to stunned targets could be nerfed 50% in PvP combat. Inquisitor’s Ire’s bonus damage to the next Divine Storm could also be nerfed 50% in PvP combat. Personally I’d like to see Vanguard of Justice removed or reworked because there’s no way to balance an ability like that for PvP, it will either be overtuned or useless. If it stays I’d like to see a 50% nerf on that as well for only 10% bonus damage in PVP combat. For Divine Arbiter, I think a 30% nerf to the extra Holystrike damage in PvP combat would be appropriate.
Now for survivability. I believe Fading Light as it currently is, is too strong however with damage nerfs it might lose some strength anyways due to it being tied to how much damage we do. If it still proves to be too strong after damage nerfs I think a 50% nerf to the Blessing of Dusk portion in PvP would be appropriate. I also think Divine Protection and Shield of Vengeance could have their cooldowns increased to 1.5 min after CDR from Unbreakable Spirit.
These are my thoughts so far and some that I believe are shared by high level players like Vanguards and Lvladen. Hope this helps!