Not sure if it has any real / significant value at the moment. If it did it would have been snatched and used years ago. It's just a hunch, obviously I don't have any facts to prove my assumptions. It can take off though if used the right way. You know those belly / thigh wraps that make people look instantly skinny? Yes, for something like that - it can be golden.
Not much. Would you really use that domain for a weight loss site? It just screams snake oil salesman/scam.
I think it has potential. I would suggest marketing it to weight loss sites. type in instant skinny in google and contact each on the first page and offer it to them. You can list it on grabthe.com or sedo and send them a link to bid on it and get them in a bidding war.. Hope this helps