I got that combination last night and had some difficulties with it myself. The group I was with didn't really understand the mechanics and made poor use of my lightwell, which made it a bit more difficult than was actually necessary. On top of this, I had two melee and a ranged who seemed to be getting hit by the fire every time in phase two.
So, after a few wipes, I figured out how to keep people up during the Claw Rage.
First of all, Daakar will target the person he's going to Claw Rage ~3 seconds before he leaps to them. You need to take advantage of this information to shift your focus to that target. What worked for me was maintaining a serendipity stack during this phase, immediately tossing a renew on that target (or PoM if not on CD) followed by HW:S immediately as they begin to take damage, followed by a hasted gheal. This was able to keep everyone up through the first half of the Rage or so, after which the tank would take it back.
When it targeted me, I'd just use two globals to pre-heal (PoM if off cooldown>Renew>Shield) and save Fade for taunt redundancy. You can also game Guardian Spirit for one of the Rages.
I would imagine this would be easier as disc, bubble/bt-penance/gheal combo is pretty win for burst.
All in all, I think these new heroics do favor mastery (for holy), as I've been relatively mana constrained without a replenishment class and many of the fights are favorable to EoL. I'm thinking about reforging back into Mastery and dropping my renew talents in favor of Darkness / desperate prayer. I never heal in raid anyway (MS shadow) - so it doesn't really matter besides enjoying the new heroics while they're still new.
Desperate prayer is a god send especially on random mass spike dmg, think flamethrower, Sinestra Orbs/Firebreath etc. Totally worth the point. Haste for holy is like last xpac ppl are just stuck on it. Plain and simple if haste was that amazing then Twilights hammer would be BiS> Andros which it most assuredly is not.
Not been playing priest that long but seems there's a heck of a lot of debate compared with some other classes... As mentioned in my previous post I have some better gear now and have regemmed a little mostly to the mixed int/spirit gems
When I raid heal (25 man)i don't tend to have any mana probate and have copied the enchants from EJ , I know I gotta research a little further so ty for the input so far, its appreciated any further advice re my gemming etc greatfully received