Is it possible to left align the page instead of the center default? I am developing a site that has the nav column left aligned and would like to continue the theme in the shopping cart.

You can only adjust margins in designer pro.

Bummer! I really didn't want to change the look of the site to fit the cart, but the other way around.

This is how I solved it:
under "custom markup" header:
<style type="text/css">
<!--
body {position:absolute; left:15px; top:10px;}
-->
</style>

Enjoy!