Your feeback sounds very melee dps influenced. Before you ask for nerfs or start talking about pvp going downhill since 2.1 I suggest you try out everything in pvp: melee, tank, healer, physical ranged and caster. Having played Wolves Den when it first came out it was absolutely ridiculous, the CC actually lasted the same duration as in PVE, and the name of the game was zerg the enemy healer before they zerg yours, which was awfully repetitive.
Caster is far from OP, BLM took a serious hit just recently and SMN is way too squishy, with dangerous burst conditions to be really competitive. I wonder if BLM will actually show in top of rankings anymore even on JP servers.
Going back to a spelll cancelling system would also mean that casters and healers would need the duration of their CC restored to at least 15 sec.
You complain not to be able to down a healer when you are solo, well I have some news for you: it is doable, even when they have full CDs, and that can be achieved by all DPS except BLM. I'm not gonna say it's not difficult or that it's something you can do steadily, but you seem to be completely oblivious that on top of needing to heal themselves a healer has at least 3 other people to heal. Nerf healers and we'll need to shorten matches to 4 mins because people will just die again and again.
I don't think WAR is that OP, most of the time they have good pressure for a few seconds, when focusing with another dps they easily kill something with berserk BUT that's nothing PLD can't do, by stunlocking a healer and stopping any of their heals going off. PLD is my favorite tank to be paired with, when they actually know what they are doing, their dps isn't great but the CC arsenal + their support makes for a much better tank imo.
Push Back is useful and much needed, first off magic is unaffected by it, secundo in stuff like Frontlines, as a DPS I expect my tanks to actually move into enemy lines with defensive cooldowns and push back so they can draw some attention and I can follow them, if I'm playing melee dps. Push back is nice paired with Bloodbath and when you have 4 stacks of medals it's one of those things that are useful to last a whole match.