Sorry, that was just a joke. Sarcasm is an occasional tic.
But you're making a whole bunch of assumptions that are wrong here. I'm not basing my comments on your profile picture. And while I do "see you as white," because you are, that doesn't influence my view of you as a person. I can promise you I'm not seeing you as "potentially dangerous" because of the colour of your skin.
Seems like our skin colour isn't as irrelevant to you as you think if you're making assumptions like this. I'm sure you wouldn't be making these assumptions if my profile picture was of a white guy.
Anyway, I think the confusion is coming from the fact that I don't understand how your definition of racism (which I don't quite agree with anyway) is compatible with anything else you said. Because yes, if you're saying that black people's lower IQ scores are a genetic issue, I don't see how you're not saying that black people are genetically inferior. At least by this metric.
Racial disparities in prisons could be (and are) based on many factors. Most relevant in the case of the US, in my opinion, is racism in the legal system and marginalisation/poverty. Maybe your definition of racism includes marginalisation/poverty, in which case we largely agree that racism is the main issue.
But then I'm still just as confused as before about what your 100 black/white people thought experiment was meant to illustrate. And also about why you think your belief that racial IQ differences are genetic will ameliorate racism.