Flag- is there a way to allow users to only flag themselves?
Is there a way to use a node flag instead? Out of the box, there you can restrict it to a node type and also to content only owned by the user (or not).

So if you have the equivalent of a content profile set up in d7, you would be able to set it up so a flag was restricted to that type of content and only to the node owner, which might accomplish what you are after.