Believing in equality of opportunity =/= believing in equality of outcome =/= believing in communism =/= being willing to kill people to make communism happen.

Actually falsely believing in equality of ability => being willing to kill to make equality happen. The chain of reasoning goes as follows:

1) As we know all people/groups are of equal ability, but group X is more successful then other groups, thus they must be cheating in some way, we must pass laws to stop the cheating/level the playing field.

2) We passed laws to level the playing field but group X is still winning, they must be cheating in extremely subtle ways, we must pass more laws to stop/punish this.

3) Group X is still ahead, we must presume members of group X are guilty until proven innocent, etc.

If you are seriously suggesting that believing that it is wrong for people to hurt one another, so if you're hurting someone on grounds of their race, you should stop somehow leads to wanting to have a repeat of Cambodia and kill all the educated people

No that's not what I'm saying. In the grandparent you said:

If I say that I am opposed to racism, and someone immediately leaps to defend their right to read whatever scientific studies they like - completely ignoring all of the other things that racism refers to, like you know, genocide, which I think we can agree is a pretty bad thing - then that reveals a set of values which are kinda disturbing to me. It signals that you care about whether you can read IQ-by-race-and-gender studies more than you care about genocide and acid attacks and lynchings, and would rather yell at me about the possibility that I might oppose you reading IQ studies rather than agree with me that people murdering one another is a bad thing.

My point is that not being able to read IQ-by-race-and-gender studies is likely to lead to a repeat of Mao/Pol Pot. Thus being extremely concerned about being able to read them is a perfectly rational reaction.

I want to learn social science, do research to figure out what will make people happiest, and then do that.

Unfortunately, as we've just established you have very false ideas about how to go about doing that. Furthermore, since these same false ideas are currently extremely popular in academia, going there to study is unlikely to fix this.