Should be no problem for your dps composition, I'd suggest having your lock spec demo for aoe.
There is a maximum time you have to kill the adds within before they automatically get sucked into the shield so make sure everyone is specced and talented accordingly - the only two dps checks for this fight are P1 and P2, you need to bring the boss to 75% within 3 arcane velocities and you need enough dps for the adds in P2, the rest of the fight is a joke...
You only need to kill 1 add wave. It looks like you have a great setup for adds imo. As a prot paladin I did 33% of the total damage done to adds myself. ( I was on 380k dps on the adds ).
People really underestimate tank damage on adds.
How to do the shield phase easily.
Face boss towards the middle
Everyone stack close to the shield.
Asap the adds spawn tank use barrier on the shield
Face boss towards the edge of the room.
Ranged stack in middle
Boss throws shield
Melee run to ranged, use rolls or whatever to reach them fast.
Just keep adds slowed, do not dps them.
Keep them away from the shield as long as you can.
When your tank get the CD back on barrier use it.
Repeat just like last time.
When adds spawn, kill them. Keep them slowed and burst them down, do not be afraid to use damage cds.
Fourth set, barrier.
If you just get everyone to switch to adds, especially tanks, it is trivial.