I fitted a 200W security light with a PIR sensor 6 years ago and it still works perfectly. My house had three fuses. One on live, neutral and one for the meter. A fuse on a neutral is both unnecessary and very dangerous so I rewired my house last summer. I have never experienced any voltage fluctuation or power cuts. Maybe voltage fluctuations come from bad wiring.
Fittings without an earth wire are flooding the market. IKEA being the biggest culprit in the UK of selling Chinese metal light fittings and ceiling fans with no earth wire, they should be fined by the inspectorate of imports but I guess the government do not employ anyone as is the case with no CE inspectors in UK.
Banjo if you want to make your fittings safe and conform to the UK standard add a wire fixed to the metal structure (Not the chain if fitted like a chandelier, the chain is not a good earth path).