Re: hot plug
Exactly. Because a UK double socket is usually rated at delivering 16A and the ring it is on is often 32A. So the 13A max cable/device needs protection. These days though the MCB at the consumer unit will flip long before the fuse in a plug goes if there is a short to neutral. Or the RCD will trip if there is an earth leak. Or the RCBO if you are using them, as is sensible, these days. Which reminds me of a small gripe, earth being called earth where its actually better described as a neutral reference. It is the same wire into most houses these days......
A mutli tiered or onion approach to safety which some other countries are less enthused by....