Problem is that these lay apostolates all need to be shut down, and Taylor Marshall needs to go get a real job. He has to basically poll his audience and then conform his opinions to them, or he loses his livlihood. So he's compromised by that simple fact, and he may not be consciously doing it. Occasionally you get a counter-example, such as with Gerry Matatics, who's willing to give all that up to remain true to what he believes, but he's the rare exception. Most of the others like their money and their lifestyle. Marshall puts up one video a day and makes $250K a year off his video channel, and half of them are garbage where it's clear that he didn't even prepare. Every once in a while he'll write a book, and if you played a drinking game where you took a shot every time he plugs his book during each day's video, you'd pass out drunk. He regularly takes his entire family on overseas pilgrimages ... that other people pay for.
As for distorting quotes, there's nothing new. Bishop Kelly did it with regard to the +Thuc consecrations, where he deliberately removed parts of quotations that actually hurt his case against the validity of their Orders, and Father Laisney did the same thing when he was attacking Feeneyism. What they did was tantamount to lying, and it's hard to see that coming from priests. Why do they do this? Perhaps they're just so convinced of their position that it's an extension of confirmation bias where they "filter out" stuff that their minds refuse to grasp.
That's the problem everywhere, that of intellectual dishonesty. St. Thomas explained that the human intellect was designed by God to grasp the truth, and when it doesn't it's due to bad will. So due to bad will, Bishop Kelly has preconceived conclusions. I heard from one of The Nine directly that he told them up front, "We can't say [the Thuc line] is valid, because then people will go to them." People have motivations of the will that lead to agendas that then lead to intellectual dishonesty. Taylor Marshall is in that category. I don't think that any of these men is in the category where they sit there thinking, "This doesn't back my position, so I'll distort it." They're likely only half-conscious that they're doing it.
Then with other issues, people have various psychological attachments to things and refuse to examine them with an open mind. That's the case with Flat Earth or Sedevacantism. People are so disturbed by the notion of FE that they won't take an objective look at the question. People are so attached to the notion of having some guy parading around Rome in a white cassock calling himself "Pope" that they refuse to actually look objectively at the matter of sedevacantism.
I think that if people became aware of their motivations and consciously set about making th decision to look at something with an open mind, we'd have much less error out in the world. With FE, for instance, I like everyone else went into it thinking it was a bunch of nonsense, due to the conditioning to which we've all been subjected, but I made a conscious decision, "I will have a look with an open mind and consider their arguments." And the more I looked, the more I saw how legitimate their arguments were. I look at every conspiracy theory, but I do not buy them all. I base it on the evidence. I've looked at the "Nuclear Bombs are fake" conspiracy and the "Airplanes don't need jet fuel" conspiracy and the "Universal "Mud Flood" conspiracy, but I've found not= solid evidence for these, although there is some funny-business going on with them, enough to make you wonder, but not enough to prove them. I looked a "Ann Heche was murdered" and found no evidence for it. And I've looked at the +Vigano is an Opus Dei Masonic operative, or the +Lefebvre was controlled opposition theory. When evaluating a conspiracy, the first thing I consider is whether there's a credible cui bono for a conspiracy. If I find none, I don't accept it.
In any case, people need to start making conscious decisions. "I don't really buy into sedevacantism, but I'll go see what they have to say and consider it with an open mind." or "I don't really buy Feeneyism, but let me have a look at the evidence for it." or "I'm skeptical about the validity of the +Thuc line, but let me have a look at both sides of the debate." But with these issues, they're non-starters for most people because they simply don't WANT to believe it. They've decided (act of the will, as St. Thomas indicates) beforehand that they're not going to acept a certain conclusion, so then they go in applying their confirmation bias to the issue, filtering out what they don't want to believe, very often not conscious of what they're doing. That brings us back full circle to the "ellipses" used by Marshall, Bishop Kelly, Father Laisney, and others. One would think that if they're doing it consciously, they would realize that they could get caught and exposed, and have their entire work discredited.
I highly recommend the scholastic approach to seeking the truth. You look at the arguments from both sides, including especially the arguments against the position you lean toward ... with an open mind, and you make the conscious decision that you're not going to dismiss their conclusion out of hand. You go in pretending that you know nothing about the subject and have no prior conclusion. I do this all the time. In the case of evolution, for instance, I pretend that I'm on a debate team. When I was doing debate in High School and at University, we went to tournaments where at one time we had to argue one side of an issue, and at other times the opposite side. This is the very definition of "sophistry", by the way, where you'll argue for something that you don't believe in, and lawyers do it as a matter of course, because their careers are built on it. In any case, I pretend that I believe in evolution, or believe that he earth is a globe, or believe that there's Baptism of Desire, or believe that Bergoglio is the pope, and I make the best argument I can for my position, as if I were on a debate team and have been assigned to promote the position. In all these cases, I simply cannot make a convicing case for the position ... which is why I have the positions that I have, yet I remain open to any new arguments that might come up. And I pray to God that He lead me to His truth, as that should be our motivation, to see out His truth, whatever it might be.
It helps to do some introspection. "What are my motivations? Do I have any extrinsic motivations with regard to this subject?" Is it money (Taylor Marshall)? Is it that I have non-Catholic relatives and so want to believe they can be saved (BoD)? Is it because I don't want to look foolish and look like a kook, or because I have some psychological attachment to the issue?" If one can discover any potential motivations that could lead to bias up front, becoming conscious of those motives might help to prevent them from leading you into error.