BuddyPress – Xprofile Privacy plugin
Please note: This plugin was developed in 2009 for Buddypress 1.1. It will not work with versions >=1.2. We're no longer doing any Buddypress development, so I am afraid that we cannot help you with any Buddypress related questions, not even in regards to this plugin, as the original developer is no longer working at our company. You may of course take a look at the code and see if you can make any use of it, feel free to copy, adapt and distribute at your pleasure.
BuddyPress currently doesn't support any kind of privacy control over profile data. Members of BuddyPress team are working on Privacy Component which will be part of some of the future releases, but until then this plugin can be helpful.
Xprofile Privacy plugin will give your users option to choose which profile data they want to share. Profile data can be public, viewable only to friends or be completely private. Users can set their privacy while editing profile or within Settings section in Profile Privacy part.
BuddyPress – Activity comments plugin
This plugin will enable posting comments on activity stream items, similar to Facebook. By default, comments are limited to 150 characters.
Only logged in users can leave comments on activities and delete that comments. Also, if user is "owner" of the activity stream he/she will be able to delete all unwanted comments on that activity no matter who posted a comment. Admins can delete any comments.