I want to use your plugin, but iam not sure if it fit my needs. 

I have a store with diferent vendors, who are artists that create products with their own designs. I want to use the plugin to give they a page where they can create mockups of the products and then download it. Then, they will upload the final mockup as a product image. Is that possible? I dont want the clients to create products, only the vendors. 

While FPD is not actually built to do such a thing, it should in general be possible. You can use FPD for the creation of the product images and download is also possible. The rest, the uploading as product image etc would have to be done through a different plugin or maybe simply through WooCommerce and WordPress accounts that have clearance to access WooCommerce products.