I'm sympathetic to a lot of your arguments. But for better or worse, you are going to run into a lot of people who think racism can only be practiced by people with power, and thst only white people have sufficient power to be racist. These people will eventually say "of course Black people and other POC can be prejudiced or bigoted, but they can't be racist." At that point, you can either argue with them about definitions, or you can just substitute the word "bigoted" for "racist" and say whatever you were planning to say about Black bigotry against white people. Everybody agrees that Bigotry is also bad, so you can make essentially the same points with a slightly different word.