I was talking with a friend of mine who knows a few people in the home department at bethel. Apparently, Prince was, as I noted in the title, on the board of directors. he apparently was sort of a silent partner or advisor in the whole thing. He'd give advice to the service and writing departments, and even to the GB itself.
I also heard that Prince personally designed the current facilities used for JW broadcasting and their other media production areas.
He's also converted a lot of other celebrities but they keep it quiet because they don't want to be outed by Hollywood. Pretty crazy. Hopefully we'll get a list soon.