What you've said is reasonable (and I've read your link before). I've also read that issues such as poor nutrition during pregnancy can have heritable effects lasting for several generations (so by this model, even if all the impoverished people in the world were suddenly given all the best resources, one wouldn't expect to see significant intelligence/behavior improvements until their great-great-grandchildren or so). The suggestion of environmental influences was more an argument against genetic explanations as a curiosity stopper (as you said, there is no reason that there should be a singular mechanism of effect for the observed disparities).

In the context of this thread, though, I was replying to the question of whether simply pointing out the statistics might be seen as overt racism by outsiders. "Blacks are over all less intelligent and more prone to violent crime as compared to whites and Asians" sounds very much like what the educated nineteenth century racists said, the same way "I like eugenics" sounds like "I like genocide" to someone who could reasonably expect to be victimized by policies based on those ideas.

(Similarly, "Blacks are less likely to be employed compared to whites, all things equal" and "blacks are disproportionately likely to be targeted by police" sound like naive progressivism, but they are also true statements.)