Alas, the overarching bellows and screams of the more casual people of the community really dictate the difficulty level of content that's released.
Even if it's something that's meant to be pursued only by the more skilled populace, I get this impression that if the casual populace feels left out despite it being content not MEANT for them, they'll just cross their arms and demand to somehow be included without wanting to improve themselves through practice and work.
I remember something ridiculous about how the Feast ranking exclusive rewards were somehow being made more accessible to everyone now, which to me seems pretty sad for the people who actually did work for it, just as an example of the problem above.
The one thing I do have to disagree with you upon is the "unforgiving imbalance" between jobs. I can honestly say that was actually one of my least favourite things about FFXI: the job exclusion. It didn't matter how skillfully you played PUP, you were just mechanically never ever going be comparable to something like SAM/WAR/DRK in terms of damage in anything. I don't think I ever want to go back to that level of "job imbalance". Even if it meant that certain jobs had really niche unique applications.
It's kind of the same problem with gear in FFXI too. I'm pretty sure I spent more time organizing my spellcast file/organizing my damn inventory/overlooking every situational -damage%, -magical damage%, haste with -damage%, don't switch my main body out while I'm under this status but change it out if I don't have this status... (it goes on really) more than actually playing the game. This is all of course, assuming the spellcast file actually runs properly.
That was too much.
While I think FFXIV could definitely use a bit more branching out with customizing, and some more job unique gear stats, I think going too complex would be just as damning as being too simple.
I do agree with the raid difficulty tiers though. I think if we added one more difficulty for the hardcore players, that would be good.
We have story mode for ilv250 (Hard), our current "accessible" savage for ilv270 (Extreme), then I think there should be a ilv285 difficulty for the hardcores (No Mercy).
I think 15+ ilvs would be a fair increase. 10 wouldn't seem like enough, and 20 would maybe be a bit too much- I think that it would definitely make the hardcore players feel rewarded as this type of gear would be the cream of the crop- beyond tomestone gear and what not too. I think it should also be more tightly tuned than the other fights- it should be extremely difficult.
Just my 2 cents!