SJB,
Not sure I get your point regarding non-bolded parts. Please explain.
In the theoretical (perhaps impossible) event that the Pope becomes a formal heretic, I believe that theologians have stated he could be declared as such by a Council and deposed. Formal heresy would mean, best I can remember, that his heresy must be public and he must persist in it even when made to realize it is heretical. An ecclesiastical body would make this call, not Joe-Sede.
As, I said this is all speculative/ theoretical as this has never happened and some say it cannot happen.
Tele,
I meant "secret knowledge" that all Popes since Pius XII? have been anti-popes, all NO sacraments are invalid, etc etc. Yes it is obvious that there have been a lot of changes since VCII and the world (including a lot of Catholics) have become more secular since 1960. But this is a far cry from saying that the notion there is no Pope is somehow self-evident.