Now it seems like you are resorting to the libertarian fantasizing that used to be so common on news-for-nerds sites.
> Note, I said hush money, not extortion.
Threatening to go public with a story when the other party might feel compelled to pay hush money, is already viewed as extortion.
> Few as litigious as the USA _so far_.
The special litigiousness of the USA is due to a number of longstanding factors including its inherited common-law system that differs from most other developed countries. It is not clear why you would expect other countries to become as litigious anytime soon.
> A better set of questions here: who benefits, and by how much, with regulating currency so tightly?
The general public who can be sure that taxes are being paid fairly and they are receiving the services they should. Again, not all countries are as culturally forgiving of tax evasion as Americans, let alone those places with even less controls over the flow of cash than the USA.