Sure, you can stack those sats and sell them in the future when they're worth more, but then you could also just buy small portions of BTC every day.
That is true. How much Bitcoin could I earn by directly purchasing $15 per month of BTC; or how much BTC would collect in a month with mining having the same cost.
Purchasing BTC directly is usually going to be cheaper than mining with most micro-miners and residential electricity.
About 4TH would give you how much BTC currently, for an average month? So a few sums up, you get around 0.00024465 BTC / 9.62 USD. Less than buying directly.
Exactly; that's true (even more true) with comparable devices, though. As shown in the efficiency chart from my original post, only the last few generations of industrial miners have a lower energy per hash ratio, i.e. higher hashrate per unit of power. And again, residential electricity prices suck, especially in Europe.
BUT, you can see things differently. If you run the nano 3 at 65W, on a "solo pool", it will cost you 8.22$/month, and you will earn zero. However, if you find a block (you are a very lucky man) it will be ~4BTC instant.(after halving).
It is a lottery ticket that run every 10 minutes.
I don't think it's possible to change the pool you see predefined on the equipment. At least for now.
They did already change it; I wrote about that on page 1. Lottery mining is definitely an option, or just mine 'at a loss' i.e. lose some $ compared to DCA, but help with decentralizing hashpower. See it as a cheap contribution to the stability of Bitcoin. Also consider you still 'get' the heat output, if you have a need for it.