Ebay will ban you at some point, if there are complaints against you.
I had over 100 successful trades and ~80 positive rating on ebay from selling wow gold , and one day BOOM!
The only explanation I was given is that I am a danger to the eBay community and that they do not approve with my activity.
I was like ... WTF??? I had 100% positive feedback, so what's up with this?
The ban was given on the release day of Mists of Pandaria.
I made ~4000 euros by then by selling on ebay.de
All I can say, if that guy threatened you, he is just a scumbag trying to eliminate his competition. He has no right to threaten you, even if he has a bussiness or not, the currency is not his and he doesnt own the trade mark for this game. My suggestion is to report him to eBay for this, they take these reports seriously.
That was not cool at all