Oregon's reasoning behind not letting you pump your own gas is one of employment. When the logging there was executed the unemployment rate shot way the "fudge" up. In order to artificially create some jobs the state passed a law that you couldn't pump your own gas, thereby creating a couple of new jobs at every gas station in the state.
As for the oxygenated fuels... they can effect some engines more than others. They use that crap here in Dallas/Fort Worth during the summer as well. My dad's old van would lose 2-3 MPG right around mid-June every year.
