The deal with Charon I guess is that if Pluto would have been called a planet it would have to also been called a planet. I'm not an astronomer but if I remember correctly Charon for a long time was considered Pluto's moon but in reality they both orbit each other. They spin around a point in space equidistant from each other so one does not actually orbit the other. And it is true that Pluto's orbit is eliptical making it so that at times it's actually closer to the sun the Uranus.