Loose threads

[NegativeS]

I can't answer all of these, but...

1. The Dark Crystal

Almost certainly just a representation of Zodiark. Can't imagine they had the Endwalker model ready to go that far in the past.

2. Hydaelyn telling Minfilia to stay behind

It was stated that Minfilia was one of Hydaelyn's most devout followers, and was thought to have been chosen for that reason.

I don't think Hydaelyn intended to kill Minfilia when she turned her into the Word, nor do I think it was wholly Hydaelyn's will when she sacrificed herself to save the First. Either way, if she didn't sacrifice herself, the First almost certainly would have been rejoined, which may or may not have weakened Hydaelyn to the point where she would either die, or be vulnerable to the machinations of the Ascians.

3. Zenos' source of power

I believe the power he had came from the swords he had at the time. At the very least, Ame-no-Habakiri was said to have been "crafted ... by Susano himself and was bathed in the blood of an arcane fiend." Definitely powerful.

[Cleretic]

I think Zenos beat us the first time because some people can just do that. If you want to bring in systems logic, the game itself put forward the simplest evidence: He's level 70 all the way through Stormblood. He was literally just stronger than us.

The only other one here I have any particular feelings on is Emmerololth, and for that, I'd put forward the simple fact that 'Emmerololth died because Galuf and company dunked an entire island into the Lifestream' is by far dramatic enough to supercede 'Emmerololth was seen alive in an earlier cutscene that was probably later chronologically'. That means that whatever answer we get will be much more likely to keep Emmerololth dead. However, I don't expect it (or honestly, most of these questions) to ever get an answer larger in scale than an off-hand clarification in a somewhat relevant cutscene.

Hell, given how all but maybe three of these are about dead characters, I don't even think that's likely, and the best we'll probably get is 'dev Q&A at a con that you'll REALLY struggle to look up specifics about when you need it'.