RE: Analog Bitcoin ATM
One thing is really different with this method. I assume your computer/mobile phone really secure. if someone stole your key, you can say bye-bye to your crypto currency. If you only have private key on paper, than try it to hack. This is one side of the story. On the other side, with the address on the paper can be verified with two method. It is possible to create an sms service which you can use to validate the address. And yes you identified the key message of this idea. It works like fiat paper money, but backed with bitcoin or other crypto currency. If you want to use, just scratch the note, and read the private key to your wallet and tadaaa you have the crypto currency. I think you like sarcasm: When you get a paper money why you trust it?
That’s fair enough you can have a verification with the note. My point is, I can still print a fake bitcoin note. You will have already put your fiat into this ATM. Your fiat is already gone, and afterwards you discover this note is a fake, what do you do then? You trusted the issuer of the bitcoin note but it was fake. Then you’re screwed.
As for your last comment, sure fiat is just fiat backed by faith in the government, but at least I can spend it. The next person I trade with will definitely accept it.
Unless you get fake money. If you never had, you are lucky. In our country it is a problem, so this is why I use bank card most of the cases.