I grew up fatter than a foie gras goose and then, after a moment in apogee, dropped eight and a half stone and mostly kept it off. The trouble with transforming the exterior, though, is that like caverns measureless to man eroded by millennia of the subterranean flow of youthful experience, the interior has already been carved out. The disconnection between the exterior world's reaction to one's own exterior and one's interior reciprocation from within a body that is no longer familiar makes for a more frustrating experience, as one has never developed the instinctual tools to respond naturally. I guess in answer to the questions, in short, never and never.
The invisible are undesirable and undesired, so opportunities to develop interpersonal skills beyond the amicable or amusing are rare to none. Following a physical transformation, one becomes visible, and unexpectedly desired; but having never learned that language one is still a deaf mute in the body of a songbird.