I have been a member on many forums etc and in general have not had any real problems, however I wouldnt recommend posting address and phone number or other info like that...but age and marital status isnt bad...although I dont think they are neccesary. Having the profile totally set to private is, in my opinion, only effective if you are only going to let people view it that you already know..outside of the social network. If you meet someone one time and then add them..well..do you really know them??
To each his own though..hopefully we dont have any cyber bullies or scuba psychos here!!!!