I do something similar, I have /cast [target=focustarget] Healing Wave(Rank 7) on my resto shaman on my normal lb spam button, so he's always healing my prot pally for a small amount. Rarely goes low on mana, since he'll usually regen almost the entire cast amount of mana in a few seconds. And of course same thing, have some numpad buttons assigned to healing various people just with the resto shaman, and when everyone is taking tons of damage everyone casts chain heal on themselves (/cast [target=player] Chain Heal(Rank X))