I am looking at the facebook app right now and there aren't sync or remove options in the facebook app itself... There's a refresh interval?
Try going into the user accounts and deleting the login account for the facebook app...if that doesn't work you will just have to do a factory reset. When you do that add your facebook account to the motorola accounts/settings (this will add all your facebook contacts into your contacts list) but when you download the facebook app from the market make sure and choose the option to not sync any contacts. This should keep your sms snappy and keep the app from adding multiple facebook profiles for each contact. Also the app will add an account called "facebook login" to your user accounts. Click on that account and make sure the sync option is unchecked...sorry if this has been confusing, its hard to explain by typing.