1: Ultimately, Isobel would have died way before Ketheric anyways, all this does is accelerate the plot, which it really doesn't have to - but if the theory of the murder being Shar's doing is true, then at least that makes Shar's character stronger.
2: Grymforge was built by Ketheric, everything else was before him by a Sharran community.
3: The Mind Flayer in the cinematic IS the Emperor. This is confirmed by Gortash's personal journal (in the Counting House, High Security Vault N6), in a book titled "The Astral Prism Heist".
4-5-7: These I wrote a lot about in my reply above, so I'd prefer not to repeat myself.
6: I've actually haven't fully completed The Blade of Frontiers, as I've severely sequence broke Wyll in my many playthroughs and ultimately couldn't be arsed to complete him, lol. So this information was unknown to me - thank you for revealing it. Nevertheless, it produces a new problem: there is a new entity that can block out hivemind comms at will, so how exactly does one learn to do this at will? Same deal for Omeluum - not to mention how big of an asshole he is as well that he never revealed whatever colony he came from.
