My little padawan,
Most of your post is quite correct. But you've got something wrong about accelerating and decelerating up / downhills. Really wrong. Look it up at http://en.wikipedia.org/wiki/Potential_theory.
Then again, I'm a 'BM'-driver. Why do I feel kind of annoyed? My 120d does an average of 5.5l/100km, or 42mpg. Not all too shabby.
And yes, there *are* BMW-drivers that do respect the 'highway code', including me.
With the exception of course, that in Germany, I can legally go 140mph, and somtimes do