I want to be able to authenticate the user, list out all their friends and give them the ability to unfriend / remove some of those friends with without going through the pr
There is no API available to add or remove friends programmatically.
What is available is a dialog box your app can use to help users send friend requests, but this still requires direct user interaction
Currently no way to remove friends programmatically but fb's mobile design can be easily manipulated by a php spider.
What you can do its create a popup to m.facebook/userid for each friend.
When the user clicks on a friend the popup opens and there they can unfriend that person, that is a few clicks and its totally allowed by facebook.
<a href="http://m.facebook.com/userid"
onClick="window.open(this.href, this.target, 'width=500,height=600');
return false;">
Friend Name</a>