I generally arcane this fight, but as a trash fight fire should be ok if you keep a few things in mind.
As you are probably aware, the kill priority is the main thing about this fight. As a raid leader, I really couldn't care less about the dps of each player at the end of the fight, as long as Dreamwalker made it up, and we didn't wipe from Lay Waste.
Whatever you are doing, drop it to kill Blazing Skeletons. You don't really have the time for a living bomb to tick down, but put it on anyway, and throw as many frostfire bolts and instants that you can.
If a tank calls out that an Abom is about to die, AoE down the worms. As arcane, I'd be dropping a blizzard down on it. In your case, you are probably looking at a Dragon's breath/flamestrike/pyroblast/flamestrike rotation.
You can living bomb the suppressors. Risen mages burn rather nicely with some frostfire bolt work.
Meters are NOT important if the skeles and worms go down smoothly.