Let me expand on a few points.

2. Another user made a very detailed spreadsheet on PvP EXP and Rank data. Check that out if you want to know more precisely what you're looking at as far as how much further you need to go. (http://forum.square-enix.com/ffxiv/t...-s-PvP-Tool-V3)

3. Many great WHM/SCH players will wear VIT accessories. Generally speaking, healing is potent enough with the bare minimum MND granted from ILv80-synced gear and MP is not usually a big problem in Frontlines so most don't bother worrying about PIE. That leaves VIT as being the more important stat. Since, in PvP, healers are almost always hard-focused, a larger health pool can be essential to survival, as it allows you to...live longer. With more VIT, you can survive longer spans of time where you've not been able to pull off a heal than you would otherwise, giving you more of a cushion to survive beyond stuns and the like. In addition, remember that attacks will not interrupt spellcasts while you're effected by an absorption effect like Stoneskin - Stoneskin will become stronger for you and last longer if you stack VIT, which can buy crucial time to freecast, even if only one or two GCD's worth. Beyond that, there's also the fact that stacking VIT as a healer can allow you to eat a Limit Break 2 from a melee and still survive, where as if you stacked anything else, you'd be dead in one shot from full. I don't play a healer in PvP, but if I did, I'd definitely stack VIT.

4-6. Not only would materia not make much of a difference if you had it, but materia doesn't work at all in Frontlines to begin with. At any point in time where there is an active ILv. sync, even if your gear is not over the threshold to be synced, materia is completely disabled. This means that Frontlines, the ILv80-sync Wolves' Den, and multiple level 50 dungeons all completely ignore materia. So, as of right now, PvP materia is 100% useless in all PvP except for level 30, 40, and 50 no-sync Wolves' Den queues.