"Traditional theology disagrees, as the Catholic Encyclopedia recognizes. Even an unjust declaration of excommunication must be obeyed."
Not if the life of the Church is at stake. All your arguments lose force against this enormity. What's going on is a modernist crisis without precedence. You are using legalisms that can't apply in such an emergency.
"That in these later times there has been spread a general obscuring of the more important truths pertaining to religion, which are the basis of faith and of the moral teachings of Jesus Christ.""In this itself (discipline) there is to be distinguished what is necessary or useful to retain the faithful in spirit, from that which is useless or too burdensome for the liberty of the sons of the new Covenant to endure, but more so, from that which is dangerous and harmful, namely, leading to superstition and materialism." (Synod of Pistoia, as quoted in "Auctorem Fidei" of Pius VI)
The Jansenists thought there was a crisis too. The true traditional Augustinian doctrine had been obscured by the Popes - measures were necessary for resistance. Disciplines had been imposed by the Pope leading to "superstition and materialism".
Finally we do not separate the Pope, even minimally, from the consent of the Church, as long as that consent is not laid down as a condition which is either antecedent or consequent. We are not able to separate the Pope from the consent of the Church because this consent is never able to be lacking to him. Indeed, since we believe that the Pope is infallible through the divine assistance, by that very fact we also believe that the assent of the Church will not be lacking to his definitions since it is not able to happen that the body of bishops be separated from its head, and since the Church universal is not able to fail. For it is impossible that general obscurity be spread in respect to the more important truths which touch upon religion, as the Synod of Pistoia held.