It probably says something about your last point that one of my favorite types of Atlantis fics are "they break away from earth" fics or fics set when they're cut off from earth. (Although fics where they've been cut off from earth again because of some disaster tend to be heartbreaking for entirely different reasons.)

Your last point on the Vegas episode explains why I keep seeing AUs for the AU pop up on delicious. Also, it sounds both terrifying and awesome and I suspect I will want to punch alt!Rodney in the face.