If the buyer's country is under international sanctions, or if the buyer fails to provide a legitimate source of funds leading to the bank returning the payment, all transfer fees and exchange rate losses incurred during this period are to be borne entirely by the buyer.

Absolutely. Even if you clear customs through gray channels, local commercial insurance companies will refuse to cover third-party liability insurance due to the vehicle not complying with national traffic laws; additionally, the vehicle will definitely fail the annual safety inspection at the local DMV.

No, this is a serious customs violation. Complete vehicles (HS Code 8703) and auto parts (HS Code 8708, etc.) are subject to completely different import tax rates. Combining them on one invoice could lead to the invoice being returned by customs and may expose you to tax fraud accusations at the destination port.