The PvE "Sidekick" Shadow Priest build

[Frag]

I obviously don't qualify as some-one from much further in the raiding scheme, but as someone who studies and researches these things and as someone who has come under focus fire for saying things about the content we're about to approach, I feel it might be time to throw down.

This is going to just be an example I'm pulling out of my ass, it's not (to the best of my knowledge) the primary or only examples, but rather a handy one.
Mogrim Tidewalker

Mogrim Tidewalker, lvl 73 Boss, Health: 5,700,000, Location: SSC.

Melee Attack: 3000-5000 physical damage on tank, will crush this fight (x1.5 dmg).

Tidal Wave: A 35 yard range attack dealing 3938-5062 frost damage and reducing attack speed by 400%. Frontal arc. The debuff lasts 15 seconds.

Watery Grave: Teleport 4 players under the waterfalls. ~6000 damage after 6 seconds, and ~1000 falling damage. 30 sec cooldown.

Earthquake: 3000-4000 damage. 45-60 sec cooldown. 35yd radius from Mogrim.
---Summon Murlocs: After each earthquake, Morogrim Tidewalker summons 2 packs of 6 murlocs, one pack enters from the north, the other south. They have low HP (~17000) and hit for ~400 on plate. Around 1400 on cloth.

Summon Watery Globules: At 25% Morogrim Tidewalker stops casting Watery Grave but begins summoning Watery Globules. He summons 4, one from each grave spot, they move slowly towards a fixed player and explodes for 4000-6000 damage on impact.

I'm effectively only an alt-experienced raid healer, though I have healed for Avarice during the 60 cap and everything we've done so far on Tori. So, to my eyes that seems like a crap-ton of raid damage. PoM, PoH, Chain heal, Binding Heal all seem applicable.

Could I be wrong? Hell yes. If we want, I'll go through the T5 instances and pull up each and every single fight that appears to have a strong raid-healing component, including the trash pulls so the truly dedicated healer-types can pick them apart.

Regards,
~Frag^_^