As with any item related to a IP of a company or studio, you run the risk of them taking note and shutting you down.
If you aim to sell, without license, that is just the game. So there is no "gray area" to look for, it is pretty black and white.
Here are the possible outcomes:
1. They will not notice and you slide by.
2. They will notice but still let you slide by.
3. They notice and send a C&D.
4. If you sell too much they skip the C&D and just hit you with lawsuit for damages.
Again.... It is all part of the risk you take. And if you do get a C&D, don't try to argue the point and think you found a loophole.
Best to comply and just quietly go away as to not poke the bear.