I tend to ride exactly where you described. Where the passenger tire in a car would ride. I find that if I'm any closer to the curb, cars will buzz by me. Any closer to the curb, a driver might not notice you either. By being directly in their line of sight, I feel safer.

Ususally if I get buzzed, I move further away from the curb. That way the driver doesn't have the option, but has to move fully into the other lane.