Thanks for all the tips guys, sorry for not replying for a while, I've been away.

We are now on the verge of entering P4 and I'm now very comfortable with DPSing in P1 and P2. I am still working on the timings of P3, but it doesn't seem too hard. In P1 I am only dropping out of CS to Adlo the flatten, Succor Megaflares and to heal my target for Earthshakers if it is OT or ranged DPS. (If the Earthshakers target a Melee, our MT covers them, so no ground aoe appears and WHM heals the other.) In P2 I only drop out of CS to Adlo Flatten and to Succor for Megaflare and Rage.

The timings on my CDs seems quite tight for P3, but a few more runs should help me sort that out.