Need some WHM Speedrunning tips please

[t-a-l-a-n-m-e-r-c-e-r]

Here's what I do for Brayflox, or any dungeon run to be honest.

Always try to have Stoneskin on tank before pull.
While tank is pulling and getting close to stopping, i pop Divine Seal and Regen on tank as soon as he's done Circle of Scorn/Overpower.
Immediately switch to Cleric Stance and start casting Holy. I usually do this three times, with a 4th Swiftcasted Holy. (Sometimes I swiftcast the first Holy if timing is off.)
If this is a really big pull. That's where i pop Benediction. Because the tank might die Before Cure II is finished casting.
Then just spam Cure II. Popping Prescence of Mind if needed.
Shroud of Saints at end of pull.

/edit I would never use Medica II on trash pulls. Slow cast, big mana cost, tanks get annoyed etc.
Medica or Cure III is more efficient (For example the Illuminati Sniper pull in Brayflox).