relation between customer and product with review
Your relationships are correct, however, they would allow for a customer to have records of products they've never bought. Is this something you want? Otherwise, you'd be better off establishing the relation between Review and OrderDetails (the intermediate table for Order-Product which in your ERD doesn't have a name), rather than to Product directly. That being said, your ERD would probably be clearer if it'd be [Order]---*[OrderDetail]*---[Product], where OrderDetail includes quantity, price used, discount, special notes, etc.

Also, Rate should perhaps not be a separate entity, but rather be Review's attributes.