Tristan,
Sorry for the delayed response. There's no scroll bars that can be used on the Fan module. It should show random faces for however many users are displayed. The number of faces is dependent on the height you set as well as if the stream and/or header are displayed. The general idea is to show that people like your page, not exactly who. The number of users that like it should be accurate, and from looking at your actual Facebook page, it does look accurate to me.
Let me know if you have any other questions, or need me to clarify anything else.
Thanks, and good luck!