And what about when Ebay UK reports your earnings to the tax authority and the Ebay account holder has to pay income tax/capital gains tax on your items?

How do you protect them against this possibility?

Also, will you prove to your Ebay account holder that your goods are legally obtained? Pretty sure customers can file a charge back several years later if their device is blocked because it's reported stolen, e.g. if you're abusing warranty returns or something.