Good input, still reflects my point that cryptos are the only possible exchange at the moment. Even if we're talking IOU's or pegged assets, the underlying is a crypto.
Even if we take it a step further and use pegs for fiat based assets like USD, it doesn't solve the problem of actually transferring and accounting for dollars. The existing financial system isn't "programmable" and has no on ramp that can eliminate human intervention (or custody in some cases)
Love the third idea. Any method that eliminates counterparty risk is beneficial, and using sidechains to exchange value makes perfect sense.