You are correct about #3 - my bad for overlooking that, and I was in error when I stated that everything is infallible. It would be more accurate to say that everything in these three categories must be believed.
In your defense Randy, I would also add, that the reason everything that the Church teaches should be (at the very least) given a “loyal submission of the will and intellect,” is BECAUSE the Church is infallible.
Now to be more specific. Let’s go back to our earlier example of the death of the Virgin Mary. Here we have Blessed Pope JPII
explicitly teaching that the Virgin Mary did in fact die.
This would fall into the third category:
3) Doctrine – non-definitive (non-infallible) and requires intellectual assent (“loyal submission of the will and intellect”, Vatican II, Lumen Gentium 25), not an assent of faith.
But does this doctrine get a loyal submission of the will and intellect? NO! The clergy are teaching in opposition to the Pope, Liturgical texts, ancient and continuous teaching of the Ordinary Magisterium, and saying instead, that because it is NOT INFALLIBLY DEFINED, it is totally optional to believe or disbelieve.
This is the state of affairs we have now in the USA.

IOW, even the clergy (by that I mean parish priests -and not all of course) do NOT understand the doctrine of infallibility, and are spreading their ignorance daily. If they did understand, they would not say things like it is totally optional, instead they would reinforce the doctrine that we have been handed down, not just from Bl. Pope JPII, but also the Liturgy and the Ordinary Magisterium.
Lumen Gentium 25:
But when either the Roman Pontiff or the Body of Bishops together with him defines a judgment, they pronounce it in accordance with Revelation itself, which all are obliged to abide by and be in conformity with, that is, the Revelation which as written or orally handed down is transmitted in its entirety through the legitimate succession of bishops and especially in care of the Roman Pontiff himself, and which under the guiding light of the Spirit of truth is religiously preserved and faithfully expounded in the Church.(45*) The Roman Pontiff and the bishops, in view of their office and the importance of the matter, by fitting means diligently strive to inquire properly into that revelation and to give apt expression to its contents;(46*)