New role - product author
I think there should be a role of a product author, who can add a product, edit and delete it but he has no rights to edit/delete other products.
That would allow to build marketplaces based on WooCommerce. A store owner should be able to set a revenue split globally/per category/etc. In that way a business model of "sell your stuff at your price and we charge 15% fee" would be doable with WooCommerce!