Based on all the different articles and excerpts posted, here is my conclusion:
Do I believe that JPII and John XXIII are in heaven? Yes, per the Church.
Do I believe they are "saints" (which used to be defined as one who is worthy of emulation due to their heroic sanctity)? No.
Must one believe they are in heaven, due to the canonization? Yes.
Must one honor them for saving their souls and making it to heaven? Yes.
Must one honor them for every detail of their life, and condone this or that decision and emulate their quasi-heresy and shortcomings? Absolutely not.
Whether canonizations are infallible or not, is irrelevant. They are definitive decisions which we aren't allowed to question. But it is important to remember that the PURPOSE for canonizations is different and more limited in our post-V2 era. Saying that JPII is of the same "spiritual caliber" as Pius X is comparing apples to oranges.
In which case BXIV erred in his day by acknowledging “many great named theologians hold canonizations are not infallible,” suggesting that opposite opinion was permissible (as the lack of any condemnation of those same theologians clearly shows to be the case);
Van Noort erred in his day by acknowledging the subject was open for debate with the (correct) theological note he attached to canonizations (as were the ecclesiastical superiors who approved the imprimatur and nihil obstat);
Matters having nothing to do with the faith -being judgments, not doctrines- neither implicitly, nor as secondary objects, nor as dogmatic facts, are nonetheless binding;
Vatican I had no bearing or relavence, even though it clearly limits infallible definitions to matters of faith (and a canonization is neither part of the faith, nor is it a doctrinal definition).
No way.
Here is how I answer your questions:
1) Possibly. Who knows?
2) No.
3) According to all the foregoing, no.
4) No (Because nobody can prove they are in heaven).
5) No.
Ps: Can you point me to the part where BXIV denounces the “many great named theologians who deny the infallibility of canonizations” to back your contention that we may not question them?
Or, maybe you can supply me with the Church’s condemnation of Cajetan (or even an example of another theologian suggesting Cajetan was not allowed to reject the infallibility of canonizations), as would surely be available were it really true that we are not allowed to question them?
It seems after 15 pages, you have just done an about-face.