1) Do you mean that you want to show only subcategories if you visit the parent category? Go to Appearance > Widgets > Product categories widget > check Only show children of the current category https://prnt.sc/26qmsr9
2) Do you use any cache plugin? Do you use the built-in element to show Recently viewed products or third-party plugin? Could you provide us with WP Dashboard access?
3) Shop page displays all the products that you have. Why do you need a separate category for this?
4) Make sure that you placed your translations of theme and plugins in the System or Custom directory instead of the Author directory https://prnt.sc/26qokxu
One standard license is valid only for 1 project. Running multiple projects on a single license is a copyright violation.