1) I checked the mentioned products with the default WooCommerce theme Storefront and see the same situation https://prnt.sc/1wlswau So, problem is not related to our theme or cache plugin but to WooCommerce plugin itself. Contact WooCommerce support with this question https://wordpress.org/support/plugin/woocommerce/
I don’t see difference between add to cart button for the product with the reviews and without them https://prnt.sc/1wltkbu
2) you can manage the number of products per page from Theme Options > WooCommerce > Product catalog > Products Per Row.
3) You did not translate XStore theme. I have uploaded a translation file, with translated strings https://prnt.sc/1wlumb9 and everything works ok.
4) We don’t have option to reset single product builder options to default one. So, you can only change them. What layout are you trying to implement? Provide us with the mockup and we’ll try to help you with that.
