My website has 100000 times less features and is 100000 times less well done than this one, but I gave the possibility to users to choose whether they wanted each of these infos displayed or not (while warning them about spam, of course).
One thing the users like is that when someone has his/her birth date public and it is his/her birthday, his/her name appears between candles. Just trying to give you ideas for silly feature requests :-)