MichaelH

You are saying “sorted by value” and “keeping the posts still sotrted by date”. Could you clear that up please.

Check the template that is displaying those posts (e.g. your theme’s index.php) and see how the_time() is being used.

Related:
Stepping Into Template Tags
Stepping Into Templates
Template Hierarchy

Use two query post loops.

See query_posts().

Or use plugins such as:
* http://wordpress.org/extend/plugins/postlists/
* http://wordpress.org/extend/plugins/list-category-posts/ (uses shortcode)
* http://wordpress.org/extend/plugins/simple-posts-list/ (uses shortcode}
* http://wordpress.org/extend/plugins/nurelm-get-posts/ (uses shortcode)
* http://wordpress.org/extend/plugins/sb-child-list/ (display pages either parent or child and has shortcode)

and:
http://wordpress.org/extend/plugins/custom-post-limits/

Use offset

<?php
$args=array(
  'post_type' => 'post',
  'post_status' => 'publish',
  'posts_per_page' => 2,
  'caller_get_posts'=> 1
);
$my_query = null;
$my_query = new WP_Query($args);
if( $my_query->have_posts() ) {
  while ($my_query->have_posts()) : $my_query->the_post(); ?>
    <p><a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link to <?php the_title_attribute(); ?>"><?php the_title(); ?></a></p>
    <?php
  endwhile;
}
wp_reset_query();  // Restore global post data stomped by the_post().
$args=array(
  'offset' => 2,
  'post_type' => 'post',
  'post_status' => 'publish',
  'posts_per_page' => 8,
  'caller_get_posts'=> 1
);
$my_query = null;
$my_query = new WP_Query($args);
if( $my_query->have_posts() ) {
  while ($my_query->have_posts()) : $my_query->the_post(); ?>
    <p><a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link to <?php the_title_attribute(); ?>"><?php the_title(); ?></a></p>
    <?php
  endwhile;
}
wp_reset_query();  // Restore global post data stomped by the_post().
?>

That widget on allows 15 posts to display.

Alternatives:
* http://wordpress.org/extend/plugins/query-posts/
* http://wordpress.org/extend/plugins/wordpress-loop/
* http://wordpress.org/extend/plugins/category-posts/
* http://wordpress.org/extend/plugins/list-category/
* http://wordpress.org/extend/plugins/bns-featured-category/

Something like:

<?php
//get all terms child of category 3, then display all posts in each term
$taxonomy = 'category';//  e.g. post_tag, category
$param_type = 'category__in'; //  e.g. tag__in, category__in
$term_args=array(
  'orderby' => 'name',
  'order' => 'ASC',
  'child_of' => 3
);
$terms = get_terms($taxonomy,$term_args);
if ($terms) {
  foreach( $terms as $term ) {
    $args=array(
      "$param_type" => array($term->term_id),
      'order' => 'ASC',
      'orderby' => 'title',
      'post_type' => 'post',
      'post_status' => 'publish',
      'posts_per_page' => -1,
      'caller_get_posts'=> 1
      );
    $my_query = null;
    $my_query = new WP_Query($args);
    if( $my_query->have_posts() ) {
      echo 'List of Posts in '.$taxonomy .' '.$term->name;
      while ($my_query->have_posts()) : $my_query->the_post(); ?>
        <p><a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link to <?php the_title_attribute(); ?>"><?php the_title(); ?></a></p>
       <?php
      endwhile;
    }
  }
}
wp_reset_query();  // Restore global post data stomped by the_post().
?>

I would recommend you read and perform WordPress Backups so that you can revert back.

Related
Restoring_Your_Database_From_Backup