I think this is a very good topic. Let's be careful and stay away from hot-button modern political issues but I do think it's important to distinguish the type of activity we're talking about feeling guilty about. "Disobeying god" would be a cause of feeling guilt that would be rejectable by an Epicurean out of hand.
On the other hand causing certain kinds of unnecessary pain to someone else whom you value would likely be much more clearly a reason to feel bad oneself in a way that could be labeled "feeling guilty." "Guilt" in the sense of "blame" makes sense to me and "praise and blame" seems to be such a common situation that it is mentioned in the letter to Menoeceus.