Okay - The Fidelius Charm is, in Canon, used to hide both the Potters and the Headquarters of the Order of the Phoenix. Presumably, there were those who knew of the location of these places previously to the Charm being cast - Bellatrix would've known 12 Grimmauld Place from her childhood, for example. What I'm wondering is if her knowledge of the place disappeared, her memories of its exact location disappeared, or if she would've known the place, at least as Grimmauld Place, even if not as the Headquarters of the Order, but could not have spoken its location. How, in your opinion does the Charm conceal a place already known by someone who should not know of its location.
Next, would the Charm be able to conceal a person's identity? Why or why not? If so, in what manner - would the person disappear from people's memory as if they'd used a memory charm? Would those who knew the person previously be able to connect the dots? Or would there be a vague recollection of the old identity, having no connection to the new identity? Or something different?