Hi, some barely related speculation on the tax ID requirement: in some countries, e.g., in Russia before 2020, the import tax is only imposed on goods if their value exceeds certain monthly limit per person (independently from number of shipments), so the customs office collects tax IDs to associate incoming shipments with a certain individual. Given that the current EU import regulations impose the tax on every shipment, the tax ID collection makes little sense for me, but maybe DHL are just being cautious and conservative with their requirements.
And some more related info: I’ve recently got a shipment delivered from the US to Germany with FedEx and everything was very smooth. FedEx actually carried out the customs clearance themselves and posted me a bill a few weeks after the delivery took place (although the bill included not only the import tax, but also a service fee:) ). So I do not expect troubles with FedEx, especially if the shipments have a credible invoice/goods description.