“As bisq is not allowing communication between customers”…
That’s not true. I contacted 3 sellers when I started trading either via text or email to resolve issues, and had positive experience. There was no need for ID, just basic communication skills.
“if I get large amounts of money and cannot check the source of the funds”
Trades >10k are automatically reported by banks. Smaller trades, if banks suspects something. If you receive a bank transfer from another person, and the bank is mediator, the bank is required to do KYC, not you. If none of the aforementioned is initiated by banks, a court order is required to access your bank records; and a reason/justification is required to obtain a court order. So what is the reason why gov. would want to go through hassle to look at your account?