Side note during editing: The topic that is referenced in the current title of the episode (Why reverence the Epicurean gods?) doesn't really kick in until about the 30 minute mark, but at that point we begin to bring up an analogy that I think is useful:
One way of looking at the opening hymn to Venus, and Her role in bringing peace / pleasure to Mars at the beginning of the poem, is that Lucretius is laying the ground work to shift the paradigm from the familiar (Venus as the goddess leading the way to the best life) to the new paradigm. in which the real "god" to whom we owe respect and appreciation for leading us in the best life is Epicurus, who in god-like / savior-like / father-like way does the same thing, but with true philosophy, rather than by means of the supernatural.
Viewed in this way, when Lucretius says "Call upon Neptune/Ceres if you like...," just so long as you don't let your mind get fouled with superstition, he's saying that the real "god" to call on is Epicurus, who -- once we allow him to show us the true nature of the universe -- takes on the role of Venus in leading us properly in the pursuit of a pleasurable life.
And in the same way, piety / reverence toward the gods in Epicurean philosophy takes on a very similar positive flavor to piety / reverence toward Epicurus himself in Epicurean philosophy. That seems to me to be the best way of interpreting Epicurean participation in "religious ceremonies, in that that participation would be very analogous to participation in the Twentieth or other memorialization of the Epicurean founders and public festivals with friends.