Is that actually an UPS or just a backup battery? Can it passthrough the line power directly or does the inverter need to run 24/7?
In the latter case you might want to check how much power the inverter eats just by itself. For example, my Bluetti with 2 kWh needs a whopping 50W in idle just to keep the AC ports powered. Of course your unit looks much smaller so it should be way less but still worth measuring.
Not really, the only wifi devices are phones and IoT.