Thats interesting indeed, the 'Do the best you can with the least possible code' paradigm is challenging to a lot of people. My vote for an extra rumble would go to 'ExtendsRobot', although I know the winner will be kawigi.robot.Girl. I am not sure if such a rumble is possible, because I don't know if it can be (automatically) detected which base class is used.
Yeah, that should be fine. And LiteRumble makes it super easy to start new rumbles. I'd also be a little interested in a perceptual rumble. I think RetroGirl would have a good chance at #1.