I sell the keys down the road. I trade my pass phase for a car or lightning. Its still good, the buyer just needs to be patient or thats how it “moves”. It transfers off chain.
That wouldn't work. Since you already have in your hands whatever you bought, you have an incentive to double-spend -- and some people will do it. The Bitcoin transaction needs to confirm during your meatspace transaction. You can't drive off with your new car while the transaction has not yet confirmed.
Shit. Even a stationary asset won’t work either.