6) P 27 I may be over my head here-- could use some help. She includes the sense perceptions of sweet, bitter, etc as "conventions" as opposed to "natural"-- I think she has misunderstood.
Yeah...it's also a bit strange to quote Democritus on physics as a way of elucidating what Epicurus taught about ethics.
My take on her overall point is that Epicureans did not take things like the existing social structure, culture, traditions, laws, beliefs, etc. for granted. Those things are only to be considered useful to the extent that they provide pleasure to humans (edit: Wilson would apparently include other species here too), and not useful to the extent that they do not. In other words, Epicurus was a radical, which I think DeWitt also says, and with which I agree. She's talking about ethics.
The Democritus quote seems like a non-sequitur. He's talking about physics, not ethics. He's saying that things like flavors don't have a physical existence. Only the molecules exist. The flavor is only the way our taste buds and brain perceive the molecules, to which we assign the words bitter, sweet, etc.
If I try really hard, and squint my eyes, I can kind of, almost, see an analogy there. But really, I think she's conflating two entirely different categories of things, and creating unnecessary confusion.