If you want to remove the category description from category pages, you can look in the vertex/loop.php file for the following code and remove it or comment it out:
<?php echo category_description(); ?>
I'm not sure why it's showing the category image instead of the individual post image - that seems like something that would be caused by core WP. However; I am working on a major framework update that will include a complete overhaul of the content area, so once I get to that part, I'll see what I can do to improve customization.
Can you provide a link to a page that is having the issue with the accordion menu? That issue shouldn't be possible.