Conditional tags help (if none, don’t display anything)

For the pingbacks ul & h2 you’ll have to move it inside your mytheme_comments function, which should be in your themes functions.php file.

The tags are a bit easier, you just need to them inside the php:

<?php the_tags('<div class="postTags">',' ','<br /></div>'); ?>

So it won’t show an empty div when there aren’t any tags.