GC restrictions are the biggest cause of this, hands down. And that's one thing Square has mentioned they're considering dropping. Let's hope they go through with that in 3.2.
That's not very specific. I play only melee classes in PvP, and they work fine. I assume you mean to say that melee are in a bad spot compared to ranged. Ranged classes are hampered just as much as melee, even if their mobility is better: BRD/MCH lose damage (by up to, what, 75%?) depending on their distance from their target and all casts can be interrupted by any physical damage taken. Specific classes might need rebalancing (MNK, AST, and SMN, perhaps?), but not simply due to the fact that they're a melee or ranged class.
No, not all PvP skills need to be on shorter cooldowns. Most might, but the cooldown for Purify is all but perfect as it is. And there are a few others out there that work fine with their current cooldowns. Still, many of the PvP abilities could use a reduction for sure.
They can. PLD are an extremely powerful support class in PvP. They don't do extremely high damage (though they can still dish out some surprising burst), but they have a selection of incredible utility abilities:
- Cover (+ Hallowed Ground) - Can save integral party members such as healers from death due to physical damage.
- Shield Swipe (+ Sheltron/Bulwark) - Can completely shut down a melee for a time with Pacification.
- Flash - Applies an AoE blind. As most PvPers won't overcap accuracy to counter Blind, its a great debuff to lower enemy damage en masse.
- Tempered Will - Can safely risk cliffs without fear of knockbacks for duration. Don't underestimate how much this can matter.
- Shield Bash - Spammable stun. Enough said.
- Divine Veil - AoE, in-combat Stoneskin when healed by party members? Yes, please!
- Clemency - Extremely potent heal that can heal a target and the PLD at the same time.
Just to note: actually, Overpower does require a target that is also in range.