So how will the business know they haven't been tampered or spent or private key written down?
Hmm. Good point.
Possible solution is to print some type of verification hash on it that includes the address and timestamp?
There are paper wallets currently people can print and use seals but I wouldn't accept them like fiat, you would need a way that they were printed and don't let the printer see the private key, which would be impossible. I just don't see a solution but it would be nice.
I mean there's gotta be some way to do this, nothing is impossible here.
Bitcoin needs to have an easier time in the real world or else it will remain confined to a small portion of the population.
Well physical coins work like this but they're from a third party, maybe something like mycelium paper wallet that is coming out but it has an led that shows a public address you send the funds to it and then it prints a wallet with a bip32 private key using special paper, the passcode to the wallet would be in a square where you would have to put a seal and the seal has a chemical that when removed shows the passcode. This would be the only way i could think of and i don't know how widely it would be adopted or accepted or expensive. The only true hard part would be the seal that when removes makes the key (i assume the adhesive would have a chemical that actually makes the ink color appear)