In Rotface there isn't really any spike damage while kiting oozes except for slime spray... and when tanking rotface himself its usuallyt he slime spray. Usually, I get IceHud and monitor my health, if it stays low for a while (few seconds) I blow a cooldown because I know that next hit is coming. Otherwise, you learn to deal with the yo-yo.
Also you need to understand how the healer classes heal. Ie. A druid can't really spike heal you, so using shield wall would save you with a druid. A paladin healer will spike heal you, so last stand if you really need to, or just ride it out. Disc priests are damage reduction, so last stand is more useful in this situation. Shield block is always good for an "inbetween" when you are deciding if you need to do more.