If you don't have a merchant account set up, you don't need to run eCart. So you're looking to just have kind of a catalog type of store and get information from the user at another time to complete the purchase?
As for the date format, for example on the orders_History.php page, it displays the date like this:
<?php echo(date('m/d/Y g:m a',strtotime($row_WADAorders['OrderDate']))); ?>
if you change the date format to 'd/m/Y g:m a' your date will be changed. If you make similar changes to all the places where the date is being displayed, then you'll get your desired result.