Hello, I know this discussion is over with, but I would like to point out, that many ladies buy an extra hanging MK Charm and add it to their bag. So if the bag typically does not come with one, it would not mean it is a fake, based on a hanging charm or key / fob alone.
I know you came to your conclusions based on other reasons, just wanted to point that out. Also many ladies take charms off of one bag and place it on another. So often , when buying a 'preloved' bag, MK hanging charms are the least of what determines authenticity. Not that I am any expert, but I do know ladies that do this, including my sister. Many can even have a fake charm on them, but the bag is still authentic, I believe these hanging charms can be purchased or replaced directly from Michael Kors. Just my two cents. Have a great weekend!