Thank you for starting this thread Godfrey! I think there's a lot of useful thought there and I agree with your direction.
But what about the limit of desires? Reading the PDs and the Letter to Menoikeus, it becomes clear that desires can be unlimited, which differentiates them from both pleasure and pain. This is why the categories of desires are important to understand. These categories are a tool to help us to impose our own limits on our desires, which have no natural limit other than the "natural and necessary" desires. This then becomes one of the key methods to increase pleasure and reduce pain.
As Joshua might say, however, having identified that at least some desires can be unlimited, and that a limit has to be imposed upon them, we are, "only at the beginning" of the analysis.
Always referencing VS63 that a life that is too frugal can be just as mistaken as a life that is too extravagant, the knowledge that we need to impose a limit on some desires only gets us started. Where is that limit? How do we determine where it is? Is it possible that there are any absolute rules on limiting desires, or is it all contextual? There are probably many other questions about the application of the question.
So once we all agree, as I presume we do, that at least some desires are limitless and it will produce a more pleasurable life if we self-impose our own limit, how do we go about doing that without falling into the trap of thinking that the answer as to how much to limit is simply "limit all desires as much as possible?"
Because that "limit all desires as much as possible, and don't even think about pursuing anything that is not absolutely natural and necessary" is the clear message I get from modern writers. I don't get that from the full body of Epicurus' work at all, but focusing on "limit all desires as much as possible, and don't even think about pursuing anything that is not absolutely natural and necessary" is an excellent way to limit enthusiasm for Epicurus to Buddhists and Stoics, two groups that I would maintain are polar opposites of Epicurus.