IronCaf

It seems like they are probably caused by two different things. Kelsier practiced pushing and pulling so much that he became a bit of a savant at it. The Inquisitors had multiple spikes for pushing and pulling, so they were innately extra powerful at it. Strength from hemalurgy instead of Savantism... Maybe they are the same thing, at the end of the day?

Another problem is that WoB confirms that there are no plate tectonics on Roshar: It looks like TWoK takes place probably 300-500 years after Elantris (from cached the Coppermind continuity page and another topic on 17th Shard), so probably not close enough to support your theory. I do think you might be onto something talking about the Cymatic patterns that seem to abound on the planet. Is it possible that one occurred during/as a result of each desolation? There would be many of them in that case, but as you say we know that the whole continent is continually being eroded in the East and reformed in the West, so you would assume that such formations would become more difficult to see over time (like meteor impacts on Earth, but accelerated because we don't have High Storms). The Shattered Plains may be the most powerful instance, and also the most recent? It certainly merits consideration.

I think using Stormlight probably has similar effects on the soul as using Allomancy, but we haven't seen anything like savants because nobody on Roshar knew how to use very much Stormlight until very recently. The physical manifestations of using that much investiture, and indeed becoming physically reliant on it, have yet to be seen. I could see crystalline eyes being part of it, at least. As for Surgebinders having gemhearts, it seems more likely to me to be like what 1empyrean said above: a deepening connection between the Surgebinder and the cognitive realm via the nahel bond with the spren. That feels more realmatically pleasing to me, but maybe the real problem is a lack of understanding of how gemhearts actually work!

I was excited to hear this. He also mentions that each book of Stormlight Archive will focus on a different person representing a different order of the Knights Radiant. I had not heard or seen anything about that before (specifically the order of the KR bit). Since Eoshani gets a book, does that mean she is/will become a Knight Radiant? That seemed pretty huge to me, but maybe it was just unguarded wording? Maybe it is the Odium-counterpart order?

The signing tonight was tons of fun, and I was super pumped to meet Brandon Sanderson ! I also figured, why not share the tiny nugget he shared with me instead of hoarding it and sitting on it for all eternity, so I made an account and here I am. And he also gave me this as a sweet custom dedication: So it's official, I'm a dead Mistborn Hooray!