The point is that sales don’t factor into it in the first place. An infringing work could increase sales, and the copyright holder would still have just the same rights. Think of anime fansubs—which effectively brought Japanese anime to mainstream popularity in the west, yet are still heavily cracked down upon by license holders, and always have been.
Yes, it could. That is why you, as the copyright holder, have the final say in the matter and may take the risk or not.
Think about e.g. Warcraft. It was supposed to be a Warhammer game. The license was "revoked", so they spun up their own story/world and created a successful franchise.
The thing is, I totally am opposed to copyright and patents, yet I can see where they are coming from and I can see reasons for them.
