The pope is infallible in defining faith and morals. Not in his personal behavior.
If the RCC has popes in it like JPII, then what about all the decisions he makes? What about the blessings on others that he allegedly bestows? Are they not valid?
The offices of priest or bishop were instituted by Christ as conduits for His blessings that come from Christ. The personal faults of the man do not affect the blessings.
Aren't Catholics obligated to follow the pope at risk of losing their salvation if they don't?
Yes normally, but that does not override the requirement to avoid sin and error.
How could the Church make such a *mistake* as appointing a *bad* pope?
How could Christ make the "mistake" of appointing a bad apostle like Judas and a weak pope like Peter? Christ founded His Church upon weak men so it would remain dependent upon Him.
Could you show us where Christ instituted a priesthood in the NT ? Where He instituted a papacy?
This theology is made up out of Whole cloth
Have you ever heard of Pope Honorius? Apparently the church of his era had never heard of this dogma of ex cathedra infallibility.
Pope Honorius was condemned as a heretic by the 6th Ecumenical Council for what he taught in a letter, which he wrote as the bishop of Rome, to Sergius. The Council stated explicitly that Honorius and the others 1) taught the heresy, 2) in words "hurtful to the soul", and that 3) "the former Pope of Old Rome, who with the help of the old serpent had scattered deadly error."
Pope Leo II confirmed the decrees of that Council and also explicily stated that he too anathematized Honorius.
The anathema of Honorious also appears in the canons of the Council of Trullo.
It is repeated in the decree of faith of The Seventh Council.
For three hundred years this condemnation was repeated by all popes at their installation: “smites with eternal anathema the originators of the new heresy, Sergius, etc., together with Honorius, because he assisted the base assertion of the heretics.”
Honorius made a theological mistake because he was unfamiliar with the issues involved. His letters that disseminated the error, "in novel terms, amongst the orthodox people, an heresy ...” were around to mislead people for forty years before they were burned at the Council.
See for example, The Heresy of Honorius
Cordially,