Keep the bulk of the sci-fi outside the games. I don't like there being one system which explains the universe and I'd rather have different cultures with different answers as in "Where were you when the Dragon Broke?". Which means leaving the truth in the dark. Even if it is canon, I don't want every npc talking about the Dreamsleeve and the Godhead, because it should be super occult at best.
I was rather hoping for a Thalmor/rewinding to the Dawn/DESTROY THE ENTIRE UNIVERSE sort of thing.
Oh come on, Ancano messed about with some weird magic orb thing of untold power, Alduin just tried to reset the universe and you want to see the Thalmor do one better
in an expansion?
I never found Snow Elves interesting because they aren't sinister enough
I assume you're talking about the ancient Snow Elves, not the modern ones.
Perhaps the prince could achieve CHIM by
enantio-mantling emantliomering Magnus or some such [censored] and bring about a dragon break which turns them into light blue Altmer with frost resistance (more than that of Nords) and a "spellsword" skill group, but not the attitude. In the process they occupy Markarth (they still sought refuge in Dwarven cities, but they didn't get enslaved) and displace the Reachmen. Then they join the Empire/anti-Thalmor alliance. And before all that, some of them are vampires.
If you work against the vampires, you get a questline a bit like a more scientific
Ultraviolet (Ultravarliance) without the smoke and mirrors, but instead of turn of the millenium technology you use Restoration. If you join them, you get the Companions questline again.
Just think about something like that until it's released and you'll surely be pleased with what we're given.