Help with speed runs as a WHM

[Sleigh]

As a usual rule big pulls start on my end with a Divine Seal, Cure II, swiftcast Med II and then a Regen...

This opener is a bad idea. M2 is almost never needed in pulls, and it makes it harder to transition into DPS if you don't have Swiftcast. The opener by Deculture is similar to what I do:

DS > C2 > (adjust if he needs another C2) > Regen > Cleric Stance > Swiftcast > Holy > PoM late > Holy > Holy > Holy > Holy > play it by ear. Keep your Benediction ready, which generally isn't needed - however, there are times where you can just use Benediction to squeeze in more Holy spam to finish the enemies off.

For bosses, Regen pre-pull (there's nothing wrong with it if there are no other enemies) > CS and just DPS until the tank's below 50% HP, DS C2 > Regen > back to DPS.

You have to adjust if DPS is terrible or if the tank is badly geared/can't do big pulls.