Last thing, as for banks using the quickest and easiest way, it would seem to me that the quickest and easiest way would be to bypass the liquidity issue altogether and peg cyber tokens (with no dollar value) to fiat. And then use that. Why does the cyber token need to have any money value whatsoever? Why does the XRP have to have any monetary value? It doesn't.
Banks can just as easily make their own tokens (with no dollar value) and peg that to fiat. Which is what groups like R3 could very easily do
I don't understand what you're suggesting. If the token has no dollar value, what purpose does it serve? Do you mean it merely keeps track of who owes what to whom? If so, how do you settle those debts?
And when you say "peg that to fiat", do you mean to have one such token for each fiat currency? If so, how do you provide cross-currency liquidity? Or do you mean to peg one token to more than one fiat currency? How do you do that?
I think what you might be missing is that the main issue is moving actual value between islands of liquidity. How would a valueless token move value between, say, Europe and India?
The kind of system you're talking about (if I understand you correctly) is great for domestic payments and very similar to what many countries currently use. It doesn't move value though, so it doesn't help much with the problem Ripple is targeting.