1. They totally missed the point on the currency question. I'm pretty sure the guy was asking if D&D was moving to a more abstract wealth system, instead of accounting for coins. Based on their answer, the answer is 'No.'
I am also worried that Dave Noonan thinks that money 'disappears' once the PC spends it, and that there's no such thing as a "D&D economy." It's hardly a main point, but I hope they give a little more thought to the 'economic' consequences to rules.
2. The meaning of "Core": will include expansions and D&D Insider materials, not just the first three books.
3. Different "Tiers" do have different rules; not terribly different, but not exactly the same.
4. Psionics: Eventually.
5.a Monster Roles: intended to help DM's design challenging encounters quickly. e.g., Combine an Artillery & Defender for encounter X. Also, now monsters can use the same tactics PC's have been using.
5.b Class Roles: intended to guide player expectations. Brings focus to character design. Brings focus to group design.
6. There were sacred cows, but not a "list" from the beginning - they took things out, saw if the game still worked / felt like D&D, and put it back if the game didn't feel like D&D.
7. Spelljammer/Ravenloft - no specific plans.
8. Nothing has been 'off limits' in the design process.
9. Monsters are 'kind of' advanced by HD.