Not per sé. It's more along the lines of speculation that the Blessing is also a means of reinforcing reality, as opposed to the Echo being able to break it down.
Lahabrea and Igeyorhm fuse with the Echo, "the power to break down the barriers of existence." The former attributes their dissolution to the power granted to us by the Blessing. Either the Blessing is capable of reinforcing reality, or we've simply become so freakishly powerful with it turned back "on" we're able to beat down the Ascian Prime until the energy needed to violate Hydaelyn's law can no longer be provided.
I wouldn't presume as much yet. In both versions Y'shtola merely mentions that something is off about the WoDs. It's more along the lines of being something strange as opposed to someone strange - their character would likely not influence their aetherial signature or makeup. What makes the Ascians off in aetherial terms, isn't that they're all a bunch of megalomaniacs devoted wholly to Zodiark's return, it's that their aether is alien compared to anything on Hydaelyn. The same is likely true of the WoDs.
Maybe. Possibly. Who knows?
... there must be other types of Auracite. The only kind we ever use is specifically called "White Auracite," never just Auracite as Unukalhai describes it. Moenbryda also notes that it has a very limited containment time, so it's not suitable for use as a primal prison - aether battery.
Bahamut was kept physically restrained inside Dalamud. Perhaps Auracite was involved, but not to keep him contained, and it's a moot point anyway since he's gone (story-wise).
It's not from a film. That is Giorgio A. Tsukolas, one of the main "theorists" on the History Channel program "Ancient Aliens." Known for his wild hair and even wilder "theories," I am fond of using a certain .gif of him saying "Is such a thing even possible? ... yes it is!" as no matter how outlandish and insane any "theory" anybody comes up with may be, it is always technically possible.
Given my tendency to develop actual theories based on empirical evidence we're given, I'm not fond of such speculation. I do have some favorite hypotheses, but without any evidence to really back them up generally refrain from doing as Tsukolas does.