Well granted i don't have first hand experience of mining at the current difficulties i'd say that you'd still make more money by just buying coins than buying GPU-hardware. If you have some monster gpu gaming-rig already and some cheap electricity you might go plus. Then there are the alt-coins where i hear it's still profitable to gpu-mine.

Not everybody who uses bitcoin mines bitcoin. To be a profitable miner nowadays you need several thousands worth of hardware. Just holding bitcoin doesn't consume any electricity, in fact you can hold bitcoin without a computer. The bitcoin ecology has shifted from an everybody who participates helps secure the network to more of a server-client relationship. As long as there are several independent mining coalitions bitcoin as system is still secure.

I agree. If the microUSB standard was something closer to the lightning connector it might have been alright. But as it is now it's a fragile mess. And apple did keep one single connector for close to 9 years. No other brand of phone (or any consumer electronics really) is even close to that. Of course it would be wonderful if everyone just converged on a sane working standard of connectors with realistic lifecycles but i can't really see that happening.

I believe the solution you're looking for is called a phone. Most people have access to such a device.

In Sweden this practise is being discontinued. Premade drillholes are being filled with concrete and such. I doubt any of swedens larger infrastructure has these devices anymore.

That's not what address means in a bitcoin context. An address is more like an account, and if random people are using your account then you probably lose your money. The problem lies in proving who has the keys to that specific account and to do that you probably need direct access to the keyowners computer. And the smart ones keep their keys encrypted on offline computers.