They outright said that it would have an 'ever changing Layout'. It has a set number of floors to reach the bottom but the layout of the floors changes every time.
The added Floors means they will be extending the dungeon's length to be deeper in further patches.
It is our concern in regards to setting our expectations. They can make it, they can balance it and they can plan and limit it, but all that can come at a unreasonable price, such as substancially longer breaks between patches, Limitations on mechanics and so forth.
For example with the LB thing. IF everyone had an LB they would need to either balance content so you needed the LB or substantially nerf the effectiveness of the LBs. If they didn't, the strength of everyone having personal LBs would potentially break the content and trivialise mechanics. However if they balanced content so you needed to use them effectively it would mean one screw up by someone and either it would be a wipe or at the very least you would be waiting while they charged up their LB gauge again. That would be REALLY frustrating in pug groups. If you did the later it kind of undermines what makes LBs flashy. They just become a fancy CD which dps at least would use on CD.
The Moogle quests, which were done badly, didn't just focus on nuts. The Pomguard quests showed the lengths and dangers the moggles went to, to keep a promise to Hraesvelgr for a thousand years, even knowing it was futile and a loosing battle, just so Hraesvelgr had someone who stayed true to him and preserved what was precious to him.
Im not saying all the quests are good or even particularly good lore. There are a plenty of duds. But as far as world building goes they act as a really good tool and flesh out and give the world depth. That's one of the things about an MMO you cant get in other media. You can literally build a deep world where places you go and people you met all have their own stories that all interweave.