Apple sent out a notification to all iTunes Connect users that they must complete some EU compliance requirements. They—and the EU—don't provide guidance to determine if I am "trader”, and the compliance requirements ask for an unspecified document proving that I live at my address.
So…I just won't sell my books in the EU Mac Book Store. It's not like anyone buys from it anyway. Apple had the most onerous and obnoxious process for being able to sell stuff. Amazon & Kobo? Just provide EIN.