Just want to post a realization of mine before I forget:

I was reading through Kaeko's tests again and went through the section on Defense and VIT. I noticed then something that I had overlooked before: that VIT apparently also mitigates magical/elemental damage.

Now I know Kaeko hasn't done/released the testing on this aspect of VIT yet, but provided it is noticeable, the answer to PLD's mitigation woes may be in stacking more and more VIT.

This also begs a few questions though:
  1. Why on Earth did PLD, what is clearly an altruistic, defensive job, get STR/MND as bonus attributes and not VIT/MND?
  2. Why is the attribute point difference in switching from GLA to PLD something as low as 10 more VIT?