The threshold for VAT is now £90,000.
Forget the €10,000 threshold; that is an intra-EU threshold for EU (not UK) VAT. Provided you only sell to the EU via eBay you don't need to worry about EU VAT unless your stock is located in the EU at the point of sale. For orders under €150 (about £129.00 currently) eBay are the deemed supplier to EU buyers for (EU) VAT purposes. If the order is over €150 the buyer is deemed to be the importer and pays their domestic VAT, duty and carrier charges on import.
Give me ambiguity or give me something else.