Modify main loop query for paged and meta key

I think this will do what you want. But I still wonder whether sticky posts wouldn’t have been better…

if (is_home() && $paged == '0') {  //$paged value is 0 on 1st page and not 1 !          
        query_posts('posts_per_page=7&paged='.$paged.'&meta_key=_pull_leading3&meta_value=off');                         
      }
      else {
        // recreate the home page "loop" to figure out which posts to exclude
        $excluded = array_map(
            create_function('$post', 'return $post->ID;' ),
            get_posts('numberposts=7&meta_key=_pull_leading3&meta_value=off')
            );
        query_posts( array(
            'posts_per_page' => 7,
            'paged' => $paged-1, // since we already excluded the first page
            'post__not_in' => $excluded) );          
      }