This is great stuff Brad, and I'd say it's just as important in the day-to-day happenings of your early stage startup, rather than just to ace a Y Combinator interview.

I love your advice about having at least 1 person dedicated to learning about/listening to users all the time. This is so key from my experience thus far with matchist (http://matchist.com/talent).

With an early stage startup, it's not about the code at all - it's 100% about the users.