Last thing I can see for now at least from a brief glance is that there is a mention of Hemalurgy's impact of the cosmere as a whole, and while I think this could just be referring to compounding it could also be in reference to Chromium, Nicrosil, Aluminium, atium, lerasium and maybe duralumin. These all have effects on things that aren't just metalic arts, Destiny, investiture, (aluminum removing all powers, seems like it could be a way to temporarily remove someone's abilities? Wonder how this would interact with surges), connection/identity, Any *power* (atium), and All Abilites (Lerasium).
Now that I think about the wording a bit more it seems like Atium would be a more specific version of power transfer through hemalurgy? Maybe taking one specific ability and Lerasium would take all of them. This could be why Sazed hid Lerasium from Kelsier and not Atium although that is likely just because Sazed doesn't want anyone getting there hands on full mistborn powers anymore, maybe he knows something more.
Feel free to add any other ideas, will check them again tommorow morning!