The best article I have seen on this topic, by far. You've nicely captured the insecurities that motivate fear of So called "Cultural appropriation", and why this fear is trivial at best, and evil at worst. It is not as bad as racism against marginalized people, but it is a form of bigotry that does not deserve to be respected. I have my own take on the topic here.

https://medium.com/@teedrockwell/why-the-mikado-is-anti-racist-d1d81e21387

The example you gave of the Shaman's parka was wrong, as you rightly point out. It was first of all, copyright violation, as this design was created by an individual, and therefore not in the public domain. It was also a sacred image which the creator probably would not have approved for commercial use. I think a case can be made that traditional cultures should get compensated in some way when someone profits from that culture's creations. But we don't need the concept of Cultural Appropriation to insure that. That concept is only a screen for insecurities of marginalized people and bigotry against privileged people. It should die a natural death as soon as possible.