To wrap your titles in h2 just change echo $ban_titles; to echo '<h2>'. $ban_titles . '</h2>';.
If you want to limit number of titles displayed to 2 change for($i=0; $i<count($pages); $i++) to for($i=0; $i<2; $i++).
Hope it helps, PHP is not so scary after all 🙂
[edit]
How about that?
//This is the loop that pulls banner titles
function print_page_parents($reverse = true){
global $post;
//create array of pages (i.e. current, parent, grandparent)
$page = array($post->ID);
$page_ancestors = get_ancestors($post->ID, 'page');
$pages = array_merge($page, $page_ancestors);
if($reverse) {
//reverse array (i.e. grandparent, parent, current)
$pages = array_reverse($pages);
}
$i = 0;
if(count($pages)==1) {
echo '<h2>'. get_the_title($pages[$i]) .'</h2>';
} else {
echo '<h2>'. get_the_title($pages[$i]) .'</h2>';
echo '<h2>'. get_the_title($pages[$i+1]) .'</h2>';
}
}