Наверное, я нашел отличное решение, которое помогает мне найти друзей, которые не являются фанатами страниц.
$facebook_result = $this->facebook->api(array(
'method' => 'fql.multiquery',
'queries' => array(
'friends_liking_page' => 'SELECT uid, page_id FROM page_fan WHERE uid IN (SELECT uid2 FROM friend WHERE uid1 = me()) AND page_id = ' . $page_id,
'result' => 'SELECT uid, name, pic FROM user WHERE uid IN (SELECT uid2 FROM friend WHERE uid1 = me() AND NOT (uid2 IN (SELECT uid FROM #friends_liking_page)))'
)
));