I probably shouldn't be doing this after people indulged me in my "Regula - Kefka" theory (though I don't think anyone really bit) but...

Pretty sure we're "done" done with Heavensward as a storyline; we won't be revisiting 3.0 areas to learn more details about the Dragonsong War and such since we already know the whole truth. Instead we'll be revisiting 2.0 areas probably, since if 4.0 is going to take us to Ala Mhigo and the only route there through Ishgard is via Xelphatol, I doubt it's going to be our primary entry point. Capturing Castrum Oriens and then using it as a staging ground for the war seems most likely...

... though if Alisae is going to take the protagonist role from Alphinaud for 4.0, whether or not we'll be working closely with the GCs remains up in the air.

(Don't think she's going to be revealed to have SMN arts, Phoenix-egi, and the Echo. Don't get greedy now!)

It was either Lahabrea or Nabriales who taught Ysayle to summon - just further proof we probably won't ever do it ourselves, since we know better than to trust the Ascians.

Ramuh's conjecture on light and darkness was just that - conjecture. He's only a few centuries old (~1,500 years tops) so unless he has access to Hydaelyn's memories he doesn't really know the truth behind it all. He was basically doing as we do here - "theorizing."

I remain unconvinced the WoDs and the people from Unukalhai's tale are one and the same. Their MOs are vastly different and we've not seen the WoDs do anything but kill Ravana, rough us up, and then observe from a safe distance. My hypothesis is that they're extra-continual WoLs from a "reflection" whose world was destroyed - in the 7th Umbral Calamity, no less - brought here and observed by Elidibus to get revenge on Hydaelyn by striking at an opportune moment to make bad go worse. Somehow. Somewhere. Sometime. Eventually. Possibly.