The contact form does not specify the message body in the body tab because it comes from an include file, WA_Universal_Email > Templates > contactus.php. If you would like to add in a custom message body make sure to make a backup of your contact page first then open it up and you can add in your own body. Any place that you want to show the information entered into the form just use the bindings tab to drag and drop values onto your page.
If you do not want the default message body to be present you will need to edit the WA_Universal_Email > WAUE_contact_1.php file and remove the include, in here look for the include code near lines 42-44:
require_once(dirname(__FILE__) . ("/Templates/contactus.php"));
$contents = ob_get_clean();
This is the part you will need to remove if you do not want the default message coming through.