If I had some complaints to lobby, they'd be the following:
1) Servers are too full. This leads to issues like overcrowding FATEs, zone lag/congestion, and severe economic swings when something is suddenly flooded. I've said it before, but I feel like the server pool needs to be doubled, transfers to remain free (but weekly restricted), and a means to set up parties with folks on other servers to be established.
2) Crystal shard farming is obscenely unfun. There are multiple ways to remedy this. As nodes increase in level, they can pump out more shards by default. Alchemists could get a synth to convert crystals up or down tiers. All enemies could be assigned a specific crystal type to drop at a fair pace. The GP abilities could be cut from 400 to 50-75. Or on the other end of the craft spectrum, all recipes would only use 1 crystal. Overall, it's not uncommon for a craft to cost more in shards than it does base materials, and that's pretty darn stupid.
3) There needs to be an open world area with nothing but level 50-52 mobs. Main purposes here are to facilitate timely spiritbonding sessions and giving max level players a good place to level their chocobos. Toss in some epic FATE chains while you're there.
4) Some mob families could use some higher densities. Some don't even have open world counterparts like flans, which have a drop used to make a potion within the Alchemy quest line. The sheep in Coerthas serve as an example here. While recently improved, it's still not uncommon to see people at all the 4-6 pop spots. Fleece is just something even max level weavers need a lot of to produce their goods.
5) Good things to spend company seals on. Unique craft materials, ilvl70-80 armor, I don't care. Just something for people who favor open world play to not feel so shackled to dungeons and queues, which 2.1 only seems to be strengthening with more dungeon incentives.
6) Chimera and Hydra need to be DFable. Too often I see DPS jobs shouting for hours and that mirrored my own experience on BLM. Add these to the pending "daily rotation" too. If it helps, you could even add a casket to the end of the fight with some unique things like pets, barding, or even craft mats. Otherwise, people done with these phases have little incentive to backtrack, which basically exemplifies the issues of one-sided tiering.
Violence good. Sexy bad. Yay America.