Well, you got some good points out there but it's debatable if anything of this will grant any kind of attention from SE devs side. However, we still can theorycraft and argue about the changes that this game needs (or don't, depends on point of view). The problem with tanks, or the problem with whole FFXIV (not a problem for me tho) is that people are used to big numbers and fast action. Most of the MMORPG out there point the "fast-piece action" as the main advantage of their games, where FFXIV is quite the opposite. You got global cooldown that slows everything down, you got relatively small numbers to work around (the damage, the stats, the math behind it) and you are left without any kind of choice of making your class (cross-class skills in current state is a kind of joke). All these "flaws" makes the FFXIV something that seems "boring". You just stay there and repeat same action until you have to move or switch targets. But this is the game tempo, you cannot do anything with that, you would have to rework the battle system, remove the GCD (or make it shorten by a massive amount) and add some more cross-class complexity. In my humble opinion this will be served to us in expansions. More cross-class abilities, higher level cap and more content to work around. If we would have everything now SE would have to do step back at some point (like WoW did with oversimplifying the talent trees). I'm looking forward to what they will do in the future. Cross-class abilities are crucial here, and if pointed in good direction can be really game changing.

As for tank itself, the class is to be played as meat shield with enmity generators. You can't ask them to make tanks DPS output similar to DPS classes because what would be the point of rolling DPS then?