So, this is well written and does bring up some valid points. But there are some serious issues:

First, your comment about defining racism misses the point: The issue there was specifically whether individuals are being racist and what that means. You seem to be arguing that that might not be terrible relevant. But that doesn't undermine that discussion at all.

Another issue is that there a large set of minorities which have succeeded quite well in the US despite having had serious issues in the past. The Chinese and the Jews are excellent examples (the second curiously enough seems to be overrepresented here.)

so many people here tend to view IQ as primarily-genetic, whereas I tend to view it as more a measure of proficiency at functioning in an industrialized, highly-individualistic, mostly-urban capitalist society.

This confuses me in that you seem to be arguing that ability to function in an "industrialized, highly-individualistic, mostly-urban capitalist society" must not be genetic. But all the time traits which evolved in one context turn out to be relevant in a new environment. Incidentally, there's a fair bit of evidence that conscientiousness matters as much if not more than IQ for actually succeeding in modern societies. (See e.g. this paper).