1. I'd actually say that she killed him first, then took his Shardblade, cuz it says there was blood which there wouldn't be if he was killed with a Shardblade. Alternatively, her brother was fighting with him and Shallan tried to stop them but he used it as a distraction to kill him, and Shallan blames herself for his death.
2. Makes sense, but what about now that he's out? Would the prophecies stop? And does this mean that Taln can see the future? I doubt it, really.
3. I idea is that Dalinar's wife betrayed him somehow and he wanted to have her taken from his mind. This would explain why he doesn't exactly seem perturbed by his lack of memory.
4. Good catch.
5/6. I'm pretty sure Thaidakar and Restares are Highprinces that Gavilar thought particularly inclined to want to kill him and take power.
7. I don't think so. I'm thinking that something humanity did made them quit, or maybe the breaking of the Oathpact.
8. But what does that mean? Is it a Shard? The Vorin call Jezrien the Stormfather, but I don't think it was him.
9. That's a good thought.
11. I really don't think so. From what we've seen of Kaladin using it, it doesn't seem nearly as instinctual as Allomancy.
12. It's possible there's some kind of magic involved with it, looking at Kabsal's notes.