Post a picture of your chameleon please, not sure as to what your description of "skinny" is. She may not need to gain any weight at all. Just want the best for your chameleon.:p
Hmmmm... not completely sure, hopefully someone else could correct me if I'm wrong, but these are probobly just calcium deposits like you said. Your chameleon didn't look very happy because of his brown color, and this may be because he doesn't have a proper basking spot. Chameleons should be a...