To remove comments rss feed link (and clear othe unnecessary options) just add the following to functions.php file of your theme:

remove_action( 'wp_head', 'feed_links' );
remove_action( 'wp_head', 'rsd_link');
remove_action( 'wp_head', 'wlwmanifest_link');
remove_action( 'wp_head', 'index_rel_link');
remove_action( 'wp_head', 'parent_post_rel_link');
remove_action( 'wp_head', 'start_post_rel_link');
remove_action( 'wp_head', 'adjacent_posts_rel_link');
remove_action( 'wp_head', 'wp_generator');