Michael never gave up on trying to appear "legitimate." He was obsessed with it. Look at all the money he gave to the Church so he could be invested as a Knight of St. Sebastian, his party, and the press corps he invited to witness it--all while serving, as Vincent put it, as "the Pope" of the Commission.
TB, at least part of Michael's church contribution motivation was his effort to try and redeem himself for his murder of Fredo. His invitation to the press though is puzzling. As you state, it may have been due to his continuing effort to appear legitimate. Maybe he was fooling himself. Maybe by then he was trying to convince himself of his legitimacy with the trappings of legitimacy.
By the way, since I teach some law, I appreciate your post about the complexities of American due process and the relative ignorance of so many people about that process and its complexities. Roth's knowledge of Michael's hidden links could have set the forensic accountants on a quest to expose those links.
