On financing, test the debt using the rent after vacancy and operating costs, not the full €3,016. I’d also run a simultaneous downside case: lower collected rent, an insurance increase and the reserved major repair occurring in the same year. Risks rarely arrive neatly one at a time.
Will this be financed? A respectable unlevered yield can still produce weak or negative cash flow if borrowing costs rise or the loan needs substantial principal payments. Stress it at a higher rate and with several months of reduced rent, not merely the expected case.
With a sample that small, I would not read much into either -2.2% or 19 days until the neighbourhood boundaries are tightened. Rome listings that look comparable on price can represent very different micro-markets and property conditions.
Are these apartments already operating as serviced...
Have you entered property tax as a separate line rather than burying it in general expenses? The amount and treatment can depend on the property and ownership circumstances, so this is where I’d get Milan-specific confirmation before relying on the net yield.