Joe is devious but harmless and should be hailed for his organizational skills and music historian expertise. His skill is that of a scribe and not an editor. While ultimate communication is that of music he is not astute in politics or independant creative thought. In other words if Leonardo D'Vinci was his contemporary they would not be friends. Joe would take the side of the church, and as its disciple could betray Lenny. The saga of child abuse in the church still seems murky to me.
Rules were broken and posed quite a problem for Jou who is about rules.

A cult can be big or small. Just because the holy church is big doesn't mean it isn't a cult of BS. They have had time to perfect their craft.