You're missing the point. Permission does not have to be explicitly granted, it has to be explicitly withheld. If the IP holder does nothing you can copy and sell their design as much as you like. Cases are considered individually and precedence is taken into account when there's a dispute - which is where the grey comes…
Yes, the Super Mario example was meant as a very concrete example :) But it does not stop at the pixels. Paint a character with a red hat a blue worker suit and a moustache, and people will quickly recognize it as Super Mario. It's these tree design points that makes a character to a super mario character. No matter if in…
Ah, nice dream. But this is not correct, sorry. A super mario sprite remains a super mario sprite, no matter if you use it as a reference or not. The design is under copyright. Not the work to create the sprite. And same counts for content at Turbosquid. The artist who has created the asset has once put work into the…