This generally seems right, but what it misses is that the absence of pain is a pleasure according to Epicurus. So it's pleasure vs. ataraxia for Epicurus; it's a question of how ataraxia fits into the landscape of pleasures.
Since I am among the leaders in typos I get used to recognizing them. Probably this was to be "So it's NOT pleasures vs ataraxia....?
What I do claim is that, for Epicurus, only some pleasures (katastematic ones) determine whether a life is blessed--and that's because the absence of pain is the only pleasure that can be complete.
Yes, the "only some pleasures (katestmetic ones) determine whether a life is blessed" is where we will continue to strongly disagree.
To be clear, though, I think Epicurus absolutely endorsed the claim that a good (i.e., blessed) life is a perfect/complete one. But that was a choice. And it's a choice that fits uncomfortably with hedonism. Personally, I'm very convinced that Epicurus was right about hedonism and right that the absence of pain is a pleasure. I'm less convinced he was right that a blessed life is a perfect/complete life.
Max in my case I like to build up from the earlier premises to the higher ones, so before we even get to the implications of PD3 and PD4 there is PD1 and PD2. Where do you land there? Do you agree or disagree with Epicurus that there are no supernatural gods, that gods do not reward friends and punish enemies, and that there is no existence after death? In my case, it is because I strongly agree with him on those first two doctrines that I find it inconceivable that - despite all his other statements about active pleasures - he would have held katastematic pleasures to be the only ones that contribute to a blessed life, as you are claiming.