The speedometer thing is a real possibility, but that applies to the tailgater as well. They may be going faster than they think. As for the highway thing, I agree entirely, with certain exceptions:
In Michigan, if a police officer has someone pulled over (lights flashing, etc) traffic is required to 1. change lanes and go around the cars, or 2. slow down. It's a saftey thing, that can get you a ticket if you don't.
The second exception is M14, down by Barton Drive in Ann Arbor. Terrible, terrible. People entering the highway from a STOP SIGN to traffic going 55 MPH, right before merging with traffic going 65 MPH (oh, there is a merge lane in the same spot). Left lane, 55 MPH, let the mergers begin.
Where I live, most of the 2 lane roads don't have shoulders. Pulling over would put a person into a ditch, or worse a tree. So, I'll just do the speed limit, and let people pass me.
BTW, if someone is on my bumper to pass, feel free to do so. I"m ignoring them anyway.