You know how I said "pre-cast self-buffs"? Any buff you have on before Cover is ignored. If you want to pop a CD, do it after Covering someone. It also always ignores Hallowed, and I believe SS as well (think it ignores SS on the Covered too, hilariously enough).
I've healed a Covering PLD many, many times...and I've never seen him take more damage than he should. Covering after losing aggro vs not Covering and holding aggro always gave me the same amount of healing "trouble" (+/- a reasonable amount, comparable to mobs critting or missing extra, and this would have to do with both of those, and Cover ignoring buffs). I also can't remember a single time he died while using Cover in these instances (which would indicate much more damage being taken than normal)
Obviously, if the enemy team is stacking mages, Cover is going to be useless. Which is on reason why my pre-made team will have physical and magic DPS on it...PLD covers the heal and I can't DPS the heal down...but the caster can...and while the heal is freaking out I'm slowly killing the PLD as well.
