Well, as you know, the question of validity really comes down to the validity of the priest's ordination, the matter used for the Eucharistic elements, and the priest's words.
The priest can have all kinds of strange ideas, the "liturgy" can express certain "Protestant" ideas, etc. But as long as the priest does what he is supposed to, validity is not a question.
SD
Question: Suppose a "valid" priest is in "mortal" sin (i.e. he's been out all night at the casino, drunk and just buggered someone an hour ago). He's in a hurry and it's time for him to say mass. He loads up the chalice with the correct wafers. So ... now he's on the altar and he says the right words. Does any of this negate his power to offer a "valid" sacrifice? In other words, does God have the liberty to say "NO WAY"?