nfgo3 – if you think that the secular laws and sentencing system are too lenient on financial crimes then you’re disagreeing with the Torah. Because the Torah’s penal system for financial crimes is way more lenient than the secular system.
gavra – My understanding is that halacha recognizes Bais Din as having jurisdiction even on a dispute between a Jew and a gentile. But like you, I don’t have a source offhand for that point, though such is my strong recollection.