~1100 mile update: I have replaced the rear brake pads. That's it. Still running the stock front tire, and it still has a reasonable amount of tread left. No new issues, the bike just keeps hauling.

Cane Creek now makes a vibration-damping headset that fits this bike. I haven't tried it, but it might be of interest to folks who don't like the steering oscillations common to this type of bike.