Ambrose, thank you for your admirable summary of the current situation in the Church today, which situation is in many respects deplorable, some aspects of which you mention. But while I do not deny the truth of much of what you relate, I deny that it applies directly to this question.
Do you understand and accept the traditional distinction between the Ecclesia docens and Ecclesia discens and see the bearing it has on this matter? Because the manner in which indefectibility and the visible rule of Faith applies, which is what the theologians allude to in arguing the case for universal acceptance being a guarantor of validity, is based on the same. It is impossible for the whole teaching Church to collectively adhere to and identify a false claimant as Pope, that is why Msgr.Noort speaks of the "ordinary and universal Magisterium", which is the only authority that can make an infallibly true judgment, and this suffices to establish the point.
Now, I agree the acceptance of the Ecclesia discens is not unimportant, but this is only on a secondary level, because, as all concede the Ecclesia discens is bound to accept the judgments of the Ecclesia docens. You yourself say this when you say the one is the rule of Faith for the other.
In summary, then, it suffices to point this out - the Ecclesia discens by its nature is bound to adhere to those judgments of the Ecclesia docens which are infallibly true, and a morally unanimous judgment of the Ecclesia docens that a certain man is Pope is infallibly true, and so the conclusion follows, that the unanimous acceptance of the Ecclesia discens is sufficient to establish that the essential acceptance of the whole Church exists.
Let's take Pope Benedict XVI's election in 2005 or the current status today in 2012. In both cases, it appears to me there is a moral unanimity even under your theory and it alone of who belongs to the teaching Church today, namely a very few Bishops to whom this has passed because of common error or because they were consecrated long ago. Therefore, the notion that we are in an interregnum refutes itself.
Let me know where you disagree. God bless.