can you send a copy of the index page so i can see how the plugins are applied.
for the second question, you would modify the code to pass both query string variables separated by the ampersand:
<form action="index.php?page=itemUpdate&ItemID=<?php echo(rawurlencode($row_WADAitems['ItemID'])); ?>" method="post" enctype="multipart/form-data" name="WADAUpdateForm" id="WADAUpdateForm">