BuddyPress.org

@csbarrett 1st, you should have mentioned that you were using the Citizen Kane bp-default child theme.
2nd, the only CSS it has directly imported from the bp-default theme is the adminbar.css therefore can’t fathom what you mean by “pulling both header images” and “overriding the bp-default header.css”.
3rd, perhaps @modemlooper, the theme author, can shed some light on your theme issues.