Marketplace - View All Products OR Fix the "Add to Cart"

I am using Marketpress, Framemarket and customising my own child theme based on GridMarket.

I want my homepage to display a list of global products. I have added 'categories to the side bar' and in the content tag, i've added mp_list_global_products(); to display a lit of global products.

The result looks good however the "add to cart" button does nothing when clicked. It will process and say "added to cart" but nothing will get added. This is different compared to the /marketplace buttons which are "buy now" and take you to the root store to add to cart.

So how can I change the "add to cart" button to "buy now" in my own page, using the code above?

Or

How can I set the /marketplace page as my homepage WITH the default to show "all products" and not show product categories (which is currently does)