A friend probably dropped your name to make you paranoid. But then again, like some mentioned, Real Name request could be in play here, change your "real name" to something else and see if that person react to it and if they do, narrow it down to who has the real name request on your list that also play FF14.

Outside of that, you said all your info were No one or friends only, so i don't see much in there that could make you vulnerable. Cause i had an idea that you had the options of "Who can see my real name" Set to friends of friends too. Which could show up in PSN ID search or on other people's search of "Who you may also know".