1. Not so commonly known or undocumented features of common visual components (or how to get the most out of them).
2. What is an "intuitive" layout. What may be intuitive to one person may not be to another.
3. When to use combo box vs. radio buttons.
4. When to use toolbar vs. standard dialog buttons (e.g. bottom right, bottom center, upper right).
5. How to modify/enhance common components.
6. When/if to use a "wizard".
7. When not to customize a component – when a "common" control fits better.
8. How/when to allow "skinning" of applications.
9. When to allow user customization, when not to and how much?
10. When to use group boxes or how best to group components.
11. When to display, or not, message dialogs (e.g. "OK", "Yes/No", etc.)?
12. Alternatives to displaying a message or messages without requiring the user to click "OK" repeatedly.
13. The use of color, when it's appropriate, when it's not.

I could go on forever, but I'll stop there.

I'm curious to find out how it goes…

No. There's no evidence that the torture of KSM provided any useful information. However, what is known is that KSM provided a great deal of information before he was tortured.