Is it possible to skip certain specified pages when using < prev and next > links?

Haven’t checked the plugin you mention… but I use this solution for doing an “author” navigation.

I adjusted the functions and this should probably work without the plugin (untested).
You need to adjust the ID, and the conditions itself if you want more exclusions.

[edit: corrected functions, the queries were missing the menu_order condition]

notes:

1) the ID 99999 corresponds to the static page defined as Front Page

2) all pages must have a defined menu order, i believe if there are pages with 0 (zero) as menu order this won’t work

//PAGE.PHP
get_next_page_nav();
get_prev_page_nav();

//FUNCTIONS.PHP
function get_next_page_nav($link="%link", $title="%title") {
    global $wpdb, $post;
    $prev = $wpdb->get_row($wpdb->prepare("SELECT ID, post_title FROM $wpdb->posts WHERE post_type="page" AND post_status="publish" AND ID!='99999' AND menu_order < '".$post->menu_order."' ORDER BY menu_order DESC LIMIT 1;"));
    if($prev) {
        $title = preg_replace('/%title/',$prev->post_title, $title);
        echo preg_replace('/%link/', '<a href="'.get_permalink($prev->ID).'" rel="prev" class="next-page">'.$title.'</a> ', $link);
    }
}  

function get_prev_page_nav($link="%link", $title="%title") {
    global $wpdb, $post;
    $next = $wpdb->get_row($wpdb->prepare("SELECT ID, post_title FROM $wpdb->posts WHERE post_type="page" AND post_status="publish" AND ID!='99999'  AND menu_order > '".$post->menu_order."' ORDER BY menu_order ASC LIMIT 1;"));
    if($next) {
        $title = preg_replace('/%title/',$next->post_title, $title);
        echo preg_replace('/%link/', ' <a href="'.get_permalink($next->ID).'" rel="next" class="previous-page">'.$title.'</a>', $link);
    } 
}