I like the first Mondays idea and focusing on the Principal Doctrines, not just for new members and people new to the philosophy but having more experienced guides present to really sharpen and condense answers to the most basic questions that people have.
The doctrines should be supported I think by references to the letters as much as possible. This is so that people's first conversations are about Epicurus own words and leaving the secondary sources and commentaries for later study and conversation.