Try replacing:
<?php echo(($row_WADAallshows2['deadline'])?date('n/d/Y',strtotime($row_WADAallshows2['deadline'])):''); ?>
with:
<?php echo(($row_WADAallshows2['deadline'] && date('n/d/Y',strtotime($row_WADAallshows2['deadline'])) != "11/30/-0001")?date('n/d/Y',strtotime($row_WADAallshows2['deadline'])):''); ?>
Another solution would have been to allow nulls for that database field in the database so that it would use null instead of that weird date when no date was entered.