Below are comments sent in regarding the challenge, but which do not specifically address any one of the points in particular. The contestant's comments are in quotation marks, and my response is in italics:
"This requirement [of unity of belief without recourse to private judgment] makes little sense. The Church has not ruled authoritatively on many interpretations. A Catholic is free to interpret in any which way as long as the interpretation does not conflict with magisterial teaching" (Mario Derksen)
Note that the contestant has already failed the contest. That's like saying a Protestant is free to interpret any which way as long as the interpretation does not conflict with biblical teaching. It is just this "magisterial teaching" that is at issue in the question. What is the magisterium's position on these issues? One cannot just assert that Catholics may have a legitimate difference of opinion about the meaning of certain teachings from the magisterium (the Roman Catholic's rule of faith) and at the same time hold to some ethereal "unity of belief" within Roman Catholicism--while at the same time chiding Protestants for having differences of opinion about the meaning of certain writings in their rule of faith (the Bible).
"Since you're stating this criterion, though, I am surprised to find you quote 'Catholic' scholars that do not agree with basically anything the Church teaches, such as John P. Meier, Edward Schillebeeckx, etc. Are you being consistent here?"
Actually, this is incorrect. The Roman Catholic scholars to which the contestant refers do indeed agree with what Rome teaches; they just disagree with the contestant's interpretation of what Rome teaches. Without engaging in private judgment and proclaiming himself to be the infallible interpreter of Roman teaching, how can the contestant know that he is not the one misreading these documents? Again, the contestant has failed the challenge.