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.

Yes. Third-party service providers in logistics, inspection, customs clearance, and finance can join the platform as "service providers."

The customs of the destination country has the right to disregard the commercial invoice and reassess the value based on its internal database (such as the customs valuation red book). Any additional duties incurred are a result of the importing country's policy and are fully borne by the buyer (importer).