I do Blizzard Thunder that exchange thingie Fire Fire Fire Fire until the exchange thingie comes up again then Blizzard until mana full exchange and fire fire fire again..or something like that but yeah..gameplay is really not that versatile :/
Same on my WHM. Basically do some prebuffing if necessary cure cure cure to get a cure II proc then us that, cleanse a bit here and there. I try to break monotony with dpsing in between but that is also a normal rotation virus, aero, stone stone stone (or stone II)
And Moon is the only way to go! Mmmmwuah
THM/BLM opens up a bit more 40+, because of extra skills and having two separate "free cast" proc mechanics.
At 50, I'm settling in on Firaga->Thundaga->Fire until spent->Swiftcast if up->Flare->Trance->(Blizzaga->Thundaga->Firaga->Fire until spent, repeat until Trance is back up)
but Flare comes out of the cycle when normal adds are involved since it's AoE, I try to keep Lethargy up on the biggest damage threat, if Raging Strikes is up it needs to come out right before Flare, if Convert is up it needs to come out after Flare instead of Trance and be followed with a couple Fires, and all of this while fitting in Enhanced Thunder and Enhanced Fire procs. The first is easy, the second sometimes requires jumping into a fire cycle with half MP to not waste the proc.
While I'm doing this, I also get to try to drop Apocatastasis on the tank if a big enemy is casting something elemental.
If I pull hate during this routine, my play would be improved if I assessed the actual threat and cast Mabarrier or Wall as appropriate to whether its main WS was magical or physical, and also if I saved Wall until it began casting a physical WS. (I'm kinda bad, so I just flail a general direction on my gamepad that gets me both+Surecast.)
On pulls with standard enemies, I also need to make Sleep my 1st, 13th, 20th, and every 7th after cast, and move it up in the list if I miss a cast due to dodging an attack or casting Flare without Swiftcast. And it needs to come out immediately if another DD isn't paying attention and AoEs.
Last but not least, if the healer drops connection or dies or is busy Raising, I have to decide whether the remaining enemies can be burnt down and either go all-out or switch over to balancing Physick spam with the occasional Blizzard to keep my MP up.
And I haven't even figured out what Aethereal Step is good for, other than getting one last cast off while you're in WS range.