Banks don't work the way you think, at least in the US. ACH transfers are slow (take a few days to complete), and often expensive. Up until 5 days later, they can be reversed even after both banks agree that they've happend if the sender decides that the payment was "erroneous."

The government can and does impose "some vague policy" on what you can and can't do with your money. If they decide that you have been "structuring" your payments to avoid triggering various reports being generated, that is considered a crime. So making several payments of 9,000 might be illegal even if you've done nothing wrong (you should have done 11,000 so that all the reports could be generated, didn't you know?)

Oh and by the way people can just take money from your account via ACH transfer if they have the correct numbers. You won't get any kind of confirmation, the bank just assumes that nobody would be unwise enough to make an ACH transfer without the consent of the other party. The US generally believes in insecure infrastructure and the 500-pound surveillance and police gorilla to keep everyone in line. It works surprisingly well, to be honest.