You ask

What is your probability estimate that an AI would be a psychopath

and you give me a helpful hint:

(Hint: All computer systems produced until today are psychopaths by this definition.)

Well, first please note that ALL artifacts at the present time, including computer systems, cans of beans, and screwdrivers, are psychopaths because none of them are DESIGNED to possess empathy. So your hint contains zero information. :-)

What is the probability that an AI would be a psychopath if someone took the elementary step of designing it to have empathy? Probability would be close to 1, assuming the designers knew what empathy was, and knew how to design it.

But your question was probably meant to target the situation where someone built an AI and did not bother to give it empathy. I am afraid that that is outside the context we are examining here, because all of the scenarios talk about some kind of inevitable slide toward psychpathic behavior, even under the assumption that someone does their best to give the AI an empathic motivation.

But I will answer this: if someone did not even try to give it empathy, that would be like designing a bridge and not even trying to use materials that could hold up a person's weight. In both cases the hypothetical is not interesting, since designing failure into a system is something any old fool could do.

Your second remark is a classic mistake that everyone makes in the context of this kind of discussion. You mention that the phrase "benevolence toward humanity" means "benevolence" as defined by the computer code.

That is incorrect. Let's try, now, to be really clear about that, because if you don't get why it is incorrect we might waste a lot of time running around in circles. It is incorrect for two reasons. First, because I was consciously using the word to refer to the normal human usage, not the implementation inside the AI. Second, it is incorrect because the entire issue in the paper is that there is a discrepancy between the implementation inside the AI and normal usage, and that discrepancy is then examined in the rest of the paper. By simply asserting that the AI may believe, "correctly" that benevolence is the same as violence toward people, you are pre-empting the discussion.

In the remarks you make after that, you are reciting the standard line contained in all the scenarios that the paper is addressing. That standard line is analyzed in the rest of the paper, and a careful explanation is given for why it is incoherent. So when you simply repeat the standard line, you are speaking as if the paper did not actually exist.

I can address questions that refer to the arguments in the paper, but I cannot say anything if you only recite the standard line that is demolished in the course of the paper's argument. So if you could say something about the argument itself.....