(BunnyChain summarised nicely, so follow that advice!)
As a WHM I:

- Focus Target
- Cure I & Regen rotations
- Watch as Death Sentence starts casting
- Prepare Cure II
- Continue Cure I rotation
Like yourself, E4E and Virus are rotated for each DS, but I don't bother with Stoneskin or Galvanize.

During P2 debuff:
- Medica II (lazy healing HoT mode!)
- Regen
- Divine Seal & Cure I
- Save Virus and other healer E4E.