VisioGuy: You could do it with a single loop, by creating a counter that keeps track of what post is being displayed in the loop.
Something like this might work for you:
<?php $post_index = 0; ?>
<?php while (have_posts()) : the_post(); ?>
<div class="post" id="post-<?php the_ID(); ?>">
<?php if ($post_index < 6) { ?>
(show title, date, author, etc..)
<?php the_content('Read the rest of this entry »'); ?>
(show comment link and stuff)
<?php } else if ($post_index < 11) { ?>
(show the title)
<?php get_the_content('Read the rest of this entry »'); ?>
<?php } else { ?>
(just show the title)
<?php } ?>
</div>
<?php $post_index++; ?>
<?php endwhile; ?>
Although for the shortened excerpt, that would need a small modification. Instead of using the_content, you can use get_the_content (which will return, but not echo the result). You could simply use the substr function to shorten it, but that will remove your 'more' link. Of course you could get it first from the string, shorten it, and re-add it back, but it just depends on how complicated you want to make it ;)