To be perfectly honest, your comp is not great for intermission 1 due to lack of control. Blood DK's are the worst of the 5 tank classes for it (bring neither amazing burst damage or an AOE stun) and mages aren't very good either. Priests bring decent damage but also offer no control (unless you're horde). If you have an option to change your roster or use an alt, you might consider that if you are truly stuck on Intermission 1. However, if you can get through this phase, you'll probably be fine on the rest of the fight.
We usually build our strategies around every group having either: 2 aoe stun/interrupt, or 1 aoe stun/interrupt plus two single target stun/interrupts. So what I would suggest is:
-Warlock [shadowfury + sac'd felhunter interrupt] + Arcane Mage [counterspell (glyphing it is a good idea for arcane)]
-Shaman [cap totem plus Wind Shear] + Rogue [focus on dps, kick if necessary]
-Killing Spree and Adrenaline rush is super OP damage
Middle -> Back Right
-Warrior [shockwave or disrupting shout middle], Hunter [binding shot back right] , DK[kick if necessary], Disc [try to dps]
-Everyone else rushes the back right if they finish early
-Hunter [binding shot + counter shot] + Frost Mage [deep freeze, counterspell]
In this group, the front right is the weakest IMO. So have ranged toss a spell or two (multishot, etc.) at this group as they run toward the middle/back.
(Front is near spawn, Back is near Garrosh)
Other suggestions: you lack a druid for stampeding roar, so drums of speed would be a really good idea. Also, using your potions here will save you a ton of wipes due to 25 energy. If your damage is good you really don't need them anywhere else. Also, make sure someone hits Garrosh with an instant non-dot ability (such as fireblast) to stop him from gaining energy ASAP.
With the nerfs and ilvl increase, Intermission 1 is the only hard part of the fight remaining and is especially comp dependent in 10m. So once you get this down, the worst part is over.
Best of luck.