Still, no more issues with the headlights. I'll keep a note of circumstances when/if it acts up again.
I even found the issue with my brake lights... the damned connectors had popped off the switch (noticed it while putting the underside of the dash back together). The warning light for the brake lights still comes on, but the moment you depress the brake pedal it goes out. Getting closer - will be (if all pans out correctly) refinishing the exterior trim this weekend with the help of Dinan540.