I killed it again today with the reset: 0 deaths / beat the enrage timer.

To answer the questions:
1) I only get 1 Rot on the "Main Tank", aka where I am piloting from.
2) I instantly run out when I get the rot, I have a key (F11) it makes the main tank cast a quick self heal to top off as I'm running and makes my second paladin taunt.
3)I get 30 yards away and explode most of the time my second tank needs zero healing in this time as they have the shield absorb legendary. The explosion on the main tank can cause a lot of damage if you aren't topped off it can 1 shot you.
4) During the "ground phase / laydown bit" I just do a circle train mashing dps / self heals but never stopping the aoe is too nasty if you stand still. You can save bubble / spellwarding for this, but I prefer to use spellwarding at the very beginning when I have lust going. I then rotate bubble and spellwarding on some of the rots to keep dps as high as possible and eliminate moving.
5) Make sure you don't have forb & bubble is off cooldown towards the end of the enrage timer, when the enrage timer has like 1-2seconds left I bubble. This latest kill I beat the enrage timer by like 15 seconds.