Switch product reviews and the related products section off across the store.
Product reviews

Tick Disable product reviews to remove reviews from every product, for shops that don’t use them. The Reviews tab and review forms disappear.
Related products

Tick Remove related products to hide the “Related products” section on every product page. It applies to the whole store; there’s no per-product or per-role setting.
See also Product page extras and Variation fields.
Get the add-on: compare the plans for All-in-One Utilities Woo Add-on, then pick the one that fits your sites.