Lad,
For example, you never touched the fact that St. Alphonsus clearly believed in implicit BOD. Even if he believed explicit faith in the Trinity and Incarnation was needed for salvation, that has nothing to do with the sacraments.
What does his belief in implicit BOD do to your view about the necessity of the sacraments, since someone can have an implicit BOD without being conscious of the sacrament, of which he is unaware - as St. Alphonsus notes.
It's a huge problem for you if St. Alphonsus meets your definition of a heretic who denies what you describe as "the necessity of the sacraments," which is de fide . . . but in what sense? St. Alphonsus clearly doesn't hold your sense.
I understand this is a huge problem for you, but if you can't address maybe you should rethink a view that results in St. Alphonsus = heretic.