[Nogrod]

It may be that one of the reasons why the character of Boromir is hard to pin down with the deadly sins vs. heavenly virtues is the fact that western culture indeed carries two sets of virtues in its inheritance. One from the Middle-Age christianity and the other from the Antiquity (Greek and Roman virtues).

With the virtue-code of Antiquity fex. noble pride or anger (not hate...) are virtues: a good man knows his value and worth (not belittling oneself and thence be untrue) and knows when to anger (for example when facing injustices). I think these older virtues are near Tolkien's heart too, not only the Christian ones.