Thanks for the reply. I think I understood what you meant.
I’ve created a static page and the Page Left Sidebar does show up with product categories, cart etc. And I’ve also added a tag under some text to show products from the relevant category. Easy enough. http://www.paperwhimsy.com/amazing-alterables/
If I tell woocommerce to use the page that is working as the main shop page then it will strip out the sidebar.
On a probably related point, is there something in Pure and Simple Pro that overrides changes I make to woocommerce’s archive-product.php?
I’m using a child theme and copied the file to a woocommerce subdirectory..