Air stance is still be the best DPS stance. If it gets any buffs though, perhaps ~6% dodge at the Grandmaster level? Though I'm not even sure it needs that.
Fire is still mostly useful for undergeared Monks who need more to-hit and Ki per hit (or for Monks who want the maximum possible Healing Amp). This one I would agree needs a buff, but I have no idea what sort of buff would be appropriate.
But yes, Ocean stance needs a huge buff. Maybe an increase to saves, +5% dodge (and to max dodge), and an increase to DCs (of maybe 2 or so)?