1. The review design can be adjusted via Theme Settings -> Single product -> Reviews: https://take.ms/8WlvE
2. We have the “Verified owner” badge option that marks reviews, made by customers who bought the current product, with a special icon. https://take.ms/hR1fA try to use it and let me know.
1,2. Sorry to say but right now there is no option in Theme Settings available for that. It requires Customization and this is beyond our limitations and support policy scope. Hope you can understand our limitations.