2. Whether Bp. Webster mispronounced his words (the audio isn’t very clear) or there was a loss of attention does not render the sacrament invalid. 

This is not true.  If the words were changed enough so as to change their essential meaning, the consecration would not be valid.  SeanJohnson cited St. Thomas in this regard.

Perhaps relevant: St Boniface came across a priest who was baptizing “in nomine patria et filia et Spiritus Sancti.” St Boniface wrote to the pope, claiming this was invalid. However, Pope Zachary did not agree. Bad Latin did not invalidate the sacrament.

He does not look happy.

It's not addressed here, but mentioned in passing, because there have been dozens of long threads about this.  Some people, mostly of the SSPV mindset, consider them doubtful.  I, on the other hand, have not seen anything that would suffice to establish any positive doubt.  It is due entirely to SSPV propaganda that people have negative doubts about them.  Meanwhile, the same people that doubt the +Thuc ordinations have no issues with the +Mendez ordinations and consecration ... despite the fact that it labors under the same difficulties.  I don't have a problem with either line.

Now, there are some strange +Thuc lines that are very difficult to verify, but the main lines have little doubt about them, especially the +Guerards des Laurier->+McKenna, and the +Carmona lines.

Someone offline sent me a signed conditional ordination certificate for Terrasson, which would put that doubt to bed.

There's little doubt about the validity of the Clemente Dominguez line either per se, but I do have some questions about Clemente's training.  He was ordained/consecrated with little training, and I would have some questions about whether he could competently perform an ordination or consecration.  Part of the presumption of validity has to do with the assumption that a properly-trained priest or bishop can validly confect the Sacraments ... another reason why proper clerical training is so important.

It is my personal opinion, however, that Bishop Webster sufficiently botched the essential form during this consecration to render it positively doubtful.  Had they not released this video, there would have been presumption of validity, but with this evidence, there's now positive doubt.

This is what came to my mind.  Get out your Douay Rheims.  Read 1 Kings 13.  

Right, there's an allowance for a certain amount of botching ... especially messing up the Latin inflection (the word ending).  But he's saying that if the root of the word remains the same, it's considered valid.

But if ministerii summam becomes misterii sanum .... it's a big stretch.  I think that this is bad enough to constitute positive doubt.  

We have it on video.  If you hear something different than what I heard, it's up to you.  All I'm saying is that, based on this alone, I would not receive any Sacraments tied to Bishop Pfeiffer due to positive doubt.  Other people entertain doubts about the Thuc line in general.  Unfortunately, we don't have any relevant and trustworthy Church authority to decide this matter for us.

This could be remedied quite easily, since Bishop Webster would merely have to do it again conditionally.