I'm thinking also about what other general comments need to be said about the overall context of these observations.
One generality that comes to mind is this: That although Epicurean philosophy causes us to lose our illusions about the universe having a grand scheme of justice that makes everything come out in the end "fairly" for everyone involved, maybe at least we have in compensation that we have a clear view of the "truth."
We aren't able anymore to live under the false illusions (primarily of religion, but also of general "humanism") that we used to find so comforting, but in exchange there's something comforting about reconciling oneself to "the way things are," and knowing that whatever time we have had, we have lived it in touch with reality and did the best we could with it.
I know in my own case that I think all my live I've been prepared to accept "truth" that I didn't like, if need be. But most of all I didn't want to waste my entire life being manipulated and living under some "noble lie" as a pawn of false forces that sounded good but were - in fact - a lie! To me there is some pleasure in thinking that I did what I could even if circumstances were adverse. But to wind up at the end of life thinking that I had spent my time being a helpless pawn at the whim of liars whom I should have seen through? That would be the worst possible result.
Now I know this viewpoint has to be tempered by the "But was it in fact a pleasurable life?" analysis, referencing how Epicurus said that it is better to live under a false religion that to accept hard determinism that it is not within your power to be happy. I suppose I can imagine a scenario in which there are some truly benevolent people who do in fact keep some hypothetical other person "in the dark" throughout their lives for the sake of that other person living pleasurably.
But while I can imagine such a scenario being possible, I see no evidence that any existing human system has such a result as its goal or as its practical result. Therefore my acknowledgement of the hypothetical has not given me any reason be worried that I was in such a situation myself or unfairly rejecting such a system anywhere else. And for the same reason I don't expect that Epicurus himself found that he had to worry about adopting a religion so as to avoid the clutches of the hard determinists.
There's a pleasure in using one's mind and doing what one can to find out the truth and then apply the lessons learned, and at least from my point of view that pleasure is worth an awful lot.
(Ha -- and of all the ways I could describe it, would I ever think of referring to that pleasure primarily as "absence of pain" or "katastematic"? Not in a million years.)