The main product is always shown, while the others selected in administration panel will be randomly shown.
No, the integration with YITH WooCommerce Wishlist is available both in the free and in the premium version of the plugin.
If you have enabled the option Hard Crop, you have to regenerate images for all products to display them all of the same size.
Yes, the plugin supports importing and exporting the information related to frequently-bought-together products into a .xml file using the default WooCommerce import/export tool available in Tools > Export > Products.
Yes, you can either add the variable product and let the customer choose the variation, or add a specific product variation. 🙂