The aminunculory were in vanilla, I think, but they were basically just sections of the ruins that, in lore, produced automatons. It is never said explicitly, but I reason that for ruins to still have automatons after a few thousand years, they would need to be able to make more on their own. 

Now, the Aetherium was part of Dawnguard. It is a strange, glowing material that can only be forged in the Aetherium forge. It can make a few unique Dwemer items, but the exact nature of its power is never explained in game. 

Oh, and I suppose we should do something with Saras. I just can't think of a way to bring up his past in a way that makes sense. He wouldn't hide it if asked (at least if asked by someone important).