Healing and you

Now i know you have your healers and this is no way means you should adopt my ways but this is what i use to raid heal and main tank heal in MH and BT and have yet to have my tank die unless it was a full wipe for some other reason. It's very fast and requires very good reaction times and fast hand eye coordination. But if you can pull it off you throw heals very very fast and cut back on your non-casting time.

For Cleanse:
#showtooltip
/cast [target=mouseover,help,exists] [targe=focus,help,exists] [target=target,help,exists] [target=player] Cleanse

The first line makes it so that the tooltip for the spell shows up when you mouseover the button. The macro checks to see if there is a valid target under your mouse cursor, failing that it casts it on your current target, and failing that, casts it on yourself.

For Healing:
#showtooltip
/cast [target=mouseover,help,exists] [targe=focus,help,exists] [target=target,help,exists] [target=player] Flash of Light

/cast [target=mouseover,help,exists] [targe=focus,help,exists] [target=target,help,exists] [target=player] Holy Light

For Harmful Spells:
#showtooltip Hammer of Wrath
/cast [target=targettarget,harm,exists] [target=target,harm,exists]Hammer of Wrath(Rank 4)

I like this one because I'm usually targeting the tank so that if my mouse isn't hovering over anyone for some reason, my heals will default to the main tank. So this allows me to use HoW without switching targets.

Divine Inspiration cast sequence, I usually pop this at the beginning of most boss fights so I can use it a few times over the course of the fight:

/castsequence reset=180 Divine Inspiration, Divine Favor

All of these require a raid frame, i use grid just because it's light weight and compact and you can see what is effecting who and when heals are coming in so you can cancel casting or assist heavy targeted members. I'll repeat this way to heal is not for everyone, but since i switched to using this i'm normally between 5th and 3rd in heals in my 25 raids where we run with 8 healers. No aoe or instant heals really hit paladins hard in the big fights later on.