Leaving the system plugged in in its self is not a worry. In fact I often leave my systems plugged in. Living where you do you likely have dirty power and the risk of lightning strikes. Even in a city you can encounter power issues as well. Here in Boston where I live we have a old power grid and some buildings wiring is very poor.
So I do strongly recommend you get a good UPS like [https://www.apc.com/shop/us/en/products/APC-Power-Saving-Back-UPS-Pro-1500/P-BR1500G|APC 1500].
You should make sure your outlets are properly wired and your buildings breaker panels ground service is properly tied to grounding rods or metal water pipe exiting the building.