Great

So if we had a non Bitcoin based coin like Nxt, Ripple or BitShares, and they implemented some sort of PayOnSecretReveal & SecretReveal API would that be pretty straight forward to implement into Mecury?
It's slightly more complicated than that in order to allow the deposits to be redeemed by the refund transactions, but that sort of API would be most of what is required. I don't know a lot about how these currencies differ from Bitcoin, do they still have the same input/output system, with scripting?