Need help adapting profile_privacy module

I have installed profile_privacy module and it is not working as I expected, and I need some info as to its internal workings and expectations.

UI expectations

1. I was expecting it to work on a deny/allow basis - every field is not visible until the user explicitly allows it.

2. It appears to show only publicly viewable fields. I want it to show all fields, public and private and give the options of making the publicly viewable fields visible.

Coding internals

I am not familiar with Drupal's internals, but my method of dealing it is at follows.

1. In the code where Drupal displays a user profile, modify the code that displays or retrieves the user information. Modify or adapt the code that checks whether a field is private to check whether the field is included in the profile_privacy's perrmitted fields. If not don't display it.

2. There appears to be a variable index named pp_privacy that appears to manage the profile_privacy system. I can't tell how it works or whether it is present only in the pp_module and there is no sign of it in the profile.module and user.module to see how it well affect information retrieval

3. I'd like to know how the profile_privacy data is stored, whether in the database or someplace else. I have looked in the user and profile values table and I can't see what relates to the profile privacy data.

PS. According to this thread http://drupal.org/node/93926 profile_privacy requires the buddy list module. Is that right?

The user interface appeared to work alright