This tidbit probably came from Aksel. Watching over the Waystones was apparently a duty given to the Hedgewise around the Forest of Shadows by Sigmar, which is why Aksel is aware of Waystone related laws passed in the time of Sigmar.
The book Grudgelore also talks about the other Ancestor Gods and them being the children of the main three.
I've always found the fact that Ulthuan is floating very strange. If it floats thanks to the Vortex, how did it float before it?
Personally, I don't think it was floating before the Sundering (when Malekith tried to destabilize the Vortex and destroy Ulthuan, and partially succeeded)
Supposedly, Ulthuan was fashioned from Draugnir's corpse by Asuryan after he was drained from making the Sword of Khaine and being hunted down by Anath Raema, which would be after the polar gate collapse. I can't attest to the veracity of this claim considering it's a myth, but Deathfang does mention gods literally walking around that time, so I can't imagine a floating island being beyond their ability.
The rest of the colleges won't be informed until we have results as well as the imperial decree to defend ourselves with. Even if they care they won't have a place to stand at that time. If we tell them now, with no results and no emperor in our corner, that's when we're vulnerable to them.
The Grey College doesn't fight all corruption. If it did, that'd hurt the Empire because feudalism is inherently corrupt and nepotistic and the Empire is feudal. The Grey College protects the Empire, whether that be by fighting corruption or by using it.
Why would that make him less respected/regarded? That seems like it would get more regard.
Our organisation was established to protect the Empire against subtle enemies, especially those using magic. And it was created in the context of a feudal society, to maintain that society, not fight against it. So making use of said feudal system for our ends is perfectly fine. From our POV feudalism is corrupt, but not from the Grey College´s.
I've always thought it was the OO who made Ulthuan and put the elves on it, like they rearranged most of the world.
It's never actually stated that the Old Ones made Ulthuan. In Quest, the Elves were assigned to a city named "Qt" and watched over by Draugnir. I'd guess Qt stands for the Ancient City of Quintex in Naggaroth, and that was the Elves' original home before they moved to Ulthuan at some point.
