I think your project is quite nice, but I'm an extremely private person, and don't wish to be found by random folks I went to high school with or be stalked by ex-es. So, some way to not be listed in any searchable directory would be a must. The only simple way I can see this being feasible would be to only allow "un-listed" people to find the others. If two people are both "un-listed," I'm not sure how that would work. Perhaps they would have to exchange private keys in person?

You can set permission on who can see your account, and if one does not have permission to see you then you will not appear in the search results. In particular you can set it to be completely private.

Is the profile that's edited by those who have your permission to see you visible to others who don't have your permission to see you?

Are you going to be able to keep up with the thousands of such FB-linked sites you need to opt-out from in the future? I'm a private person too, so I don't use FB.

That's one of the reasons why I've stopped development on this: nowadays the only way to get a critical mass of users on a site like this seems to be by being annoying or shady, doing things such as scraping data to build up profiles, spamming friends, etc. I have been considering though opening up the whole project on github to serve as an example and see perhaps what others can make of it.