Sorry, but most of your suggestions, while I'm sure they would improve mileage, do not absolve Ford of the obligation of meeting a reasonable facsimile of what they advertise. Saying that my car might be different than the EPA estimates is wrong, as well, since the sticker was on my car, and therefore it is the obligation of the vendor to correctly advertise the vehicle that the sticker is on. I had something similar at Honda when I walked in and a sign on a car said "Lease this car for $8/day" and it was on a fully loaded CRV. I said I would take it and they said "we'll not this car exactly." I took a picture and sent it to the attorney general as that is false advertising.
Making a claim that a car performs a particular way is part of the contract when I buy it. While YMMV, 50% has been shown to get car companies in a great deal of trouble (just take a look at Hyundai and the massive fines and car returns they are processing right now for false MPG claims on the Sonata, and that is only a 10% underperformance).