Great thread, I bookmarked quite a few talks for later viewing.
I recommend the NYU Game Center talks. Both their lecture series and their Practice conference include some gold nuggets:
https://vimeo.com/nyugamecenter/videos/page:1/sort:date
If anyone here plays Netrunner, Lukas Litzsinger, the designer talked about the experience of re-designing an existing game. https://vimeo.com/125164271