No, we mostly update Shopping Cart template with each new release of PHPRunner to make sure its compatible.
I must say that those new features are easy to add.
Add a couple more picture fields to shopinventory table (Picture2, Picture3) with respective thumbnail fields (th_picture2,th_picture3). Setup View as/Edit as settings and add those fields where you need them to appear in Visual Editor.
Subcategories will require you to add a new field parent_id field to shopcategories table. parent_id field will store the ID of the parent categories. Besides that you will need to modify inventory_menu code snippet on shopinventory list page to display categories and subcategories in hierarchical way. Don't have sample code for this task at the moment.
Manufactures (vendors) are the already. Check table shopvendors and field vendor_id in shopinventory table.