A standard household broadband connection should suffice. 4G mobile broadband also works fine with a home mining setup.

Q/P ratio related to the mining hardware? Difficult to answer..

I mine at home for the heat, so I regard the energy cost as irrelevant, as I would have heated my house with electricity anyway. Question becomes can I recoup my investment cost in satoshi terms?

Below is an example of a calculation based on an S19 miner, where I include difficulty adjustment/hashrate increase and the halvenings.

I can't run it 24/7 due to noise and warmer months where it is not needed. I have factored in a utilization rate from low (30%) to high (50%).

If you're in it for the satoshi's, it takes time to go break even..