They may have a "greater priority" but a cart without a decent checkout is a waste of time.

The filtering of products by criteria is a very powerful feature. IF you allow the criteria to be parameterised (like other carts) it can vastly reduce the sice of menu structures.

Advanced order management. As per Litecommerce Advanced Order Management. i.e. the ability to change prices, products, add new products, change qtys, remove products, change customer billing address, change delivery address, change shipping, change order status, send messages to the customer, have a set of default messages for specific status changes.etc