1. Actual second-hand reselling of bought games
2. Tactically/strategically reselling keys legitimately acquired cheaper (giveaways, review keys, differentiated pricing between markets)
3. Fraud and money laundering (e.g. stolen credit cards)
I think that the reasonable position and that of anyone not being incentivized to say otherwise would be that 1 should be allowed while 3 is already illegal and should be cracked down on.
On the 2 my position is that this is not something that should be addressed by regulation but that it's the responsibility of the publisher. Don't want to see review keys ending up on second-hand sites? Put in restrictions (like limited time) on those licenses. If the second-hand market for keys you ave away for free ends up eating at your margins, maybe you gave away too many free keys or price too high.
As for regional pricing, IMO it's both counterproductive and futile to keep national markets separated.