I hate healing FoS, simply because there's massive splash damage. Not sure if the caster trash just randomly throw spells around, AoE, or the tank just not holding aggro but everyone takes stupid amounts of damage.
Terms of blessings I usually bank on the blessing specific to spec (ret will do Kings or Might, Holy will do Wisdom, Prot will do Sanct). Though I have noticed a reasonable difference between Wisdom and Kings when healing, I just never bother to ask about it because most paladins now are retarded. Only time I get verbal is when you get a cheap one that gives out the 10-minute lesser blessings. Fuckers have the cheapest reagents of any class in the game, stop being a WoW-jew.