Yes, a clear case is just as protective as any other case made of the same material. You can find clear cases in a wide range of materials and styles so some of them will be better than others.

Pay for Mullvad and move on with your day imo. A free VPN means your data is the payment

You can pretty much just pick something on Amazon with an easy install kit to make sure it’s aligned and move on.

If she’s exceptionally accident prone, get applecare when you buy the phone.