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..

Bandwidth should not be a problem. The higher your ping gets the more stale shares you get. From traffic perspective the miner dose not have that much. Only takes a block (2mb) every 10min + some back and forth conformation on hashrate.

Not sure what Q/P ratio means but obvious the newer the miner the more btc you get per power consumed.

On older miners you get more hashrate per $. (With lower efficiency obvious)

Prices will be dependent most Lilly on the location you want to buy.

For me it’s like

s9 with 14Th per 1kWh @ 160€

S19 with 110Th per 3kWh @ 1500€