Very interesting read. I finally finished, at the expense of morning dishes.

Most of the observations that I had while reading were well summarized in the end. That was good to see. He had my eyes welling up by then. That's the clearer-mindedness and edification/resolution that I hoped would be there.
I do find it interesting that he inadvertently confirms many claims of the resistants by describing the "purge", and wishes they had simply been told it was going in a new direction, that old molds were not welcome. It is telling that it comes from someone not involved with the resistance.
The politics that were there before, are there now and likely always be there is nothing new. Disappointing, disheartening, damaging, but not new. Not for the SSPX and not for any Order under the sun at any time in history.
As for wasted vocations, it's a tough theory to prove. I have a different take from what seems to be popular here. I don't doubt there are some who fell victim to the new brand the SSPX is looking for, but I do not believe it applies to this particular author. His issues began immediately, years before the change and I believe they reflect a forced vocation rather than a wasted one. As much as individualistic modern man hates conformity, it is necessary, especially in this kind of environment. He simply could not adapt and in retrospect that ought to be obvious to him. This is not something bad about him, it is simply a fact and it can be a sure sign of not having a vocation.
There is no mathematical formula to having a vocation to the religious life. I say this as someone who can relate to the torture of "limbo", the instability of not knowing my state in life and grappling with it similarly. From the age of 15 until I met my husband, not ONE teacher/superior/director (and I had a few) was able to give me straight-forward direction on whether or not I had a vocation. Yet those same people were very accurate and insightful about others. I was very confusing to them, as I was to myself, for some unknown reason. I had all the qualities they were looking for spiritually and mentally but when it came down to living the life, I withered. I simply wasn't suited to it and I looked at a few places. In the end I do much better making my home my cloister. A person can easily have good qualities yet still not necessarily have a vocation. A person can WANT a vocation with every fiber of their being and not necessarily have a vocation. And we all know that person who did NOT want a vocation yet has one! It's a surprising and seemingly illogical business and always will be.
That's what jumped out at me from every page. If they did him any great injustice it was in keeping him longer than they should have. But even then, he says frankly that he went in distrustful, that he did not open up to his spiritual director and that he sometimes passive-aggressively and othertimes openly resisted him. He also admits several times that he went back with the wrong intentions. How could he possibly think that would end well?
The standoff between him and his spiritual director is very unhealthy but I have to reserve judgment on that since I will never hear the other side of that story. As much as he speaks of honesty and integrity, I don't see that in the way he handled himself. He ought to have said everything clearly and taken the consequences of being deemed unfit or of "bad spirit" (if that's what was going to happen) or left of his own accord. Presenting only half of himself for fear of losing his dream of having a vocation was deceptive and put his superiors at a great disadvantage for clear discernment and proper guidance. I would bet the horror stories go both ways there.
I also have difficulty with his perspective that everyone was feeling the way he did or if they didn't they were simply repressed or had no character. His idea of having "character" is largely based on his own larger than life character and his idea of "active" is overly physically based. Not everyone has his extremely high strung energy and I would bet that many find the seminary life to be quite "active", if they aren't obsessed with a physical interpretation of the word. There are active souls and active minds. A little bit of recess, some daily chores, that's about what most of us get, whether in the seminary or not. And the seminary is a dedicated intellectual pursuit. It would be odd for them not to be focused 100% on studies and be exercising hours a day.
Not only that but he admits that being larger than life, he could not handle himself. Yet he resisted help. How could that possibly have transitioned well into priesthood? Was all of this turmoil going to magically disappear with Ordination? Somehow I doubt it. Ordination, like marriage, is when the real work begins. If he could not handle SSPX seminary, I doubt he could have handled SSPX priesthood. That's where I think Ladislaus has a good point. In other times there were mutiple choices which could suit all different types. Now it's pretty slim picking. If you don't suit one or two choices, you're out of the game. I don't consider those lost vocations though. God put us in the here and now knowing full well what the situation is. To my mind it means there is no vocation present. Otherwise we'd be saying that He gives vocations where there is no way of materializing them. That would be especially cruel.
He should have seen a psychiatrist. He took that as an insult but if seminary life was driving him crazy, which it clearly was, (and I say this as someone who would go crazy in the convent, not as someone pointing a finger) it would have helped for them to know if he had any underlying condition or if it truly was just the life that was too much for him. I don't see this as the psychological weapon he thinks it was. Reacting badly to the life IS one of the ways that the lack of vocation can manifest itself. It doesn't mean he is crazy or bad-willed. Neither does it take away that he is gifted and magnanimous. It simply means no vocation to the SSPX. But since he was bent on having a vocation no matter what....this was just another way that he could block their ability to discern. (As a side note even if he had had a condition it is not necessarily an impediment. It depends on the condition and its treatment. There is at least one SSPX priest that I know of with a family condition, who broke down in seminary yet was ordained after a few years of sabbatical.)
As for the favorites thing, it seems natural that he would catch their attention if he is as gifted as he is. They would be robotic and not human if they didn't notice and pay attention to his potential. It seems like they'd be damned if they did and damned if they didn't try to accomodate his individuality as much as they could. One of his greatest complaints is about conformity yet it's clear by his own account that they tried several different ways to help him adapt. He had a voracious mind, they fed it. He needed more exercise, they let him run. He was breaking down, they let him skip a class. He needed more time to talk, they let him see his director more often. If these accomodations made him feel worse, it is not their fault for trying. Nor is it necessarily his fault either. Again, to me that simply underlines a lack of vocation, with them at least.
That's not to say that someone with a vocation breezes through. They all have enemies, witness injustices, are stung by meanness and other sins committed by their superiors and classmates etc... but they receive the graces to get through it and grow, even if it seems impossible at first. In this case, the author either didn't receive those graces as a sign that he wasn't meant to be there or he rejected them. I have difficulty believing he rejected them. I think he was good-willed and very generous, it just wasn't for him.
I feel for the torment he went through. It is not an easy way to go. It would be much easier to be told yea or nay right off the bat. But it's not always that simple. Sometimes we get in our own way and in His wisdom God allows it. Othertimes we do everything right and still God allows us to "fail". I don't know what his intentions are in putting this out for the public but it takes a lot of courage to make oneself so vulnerable. It cannot have been easy for him to relive it all in writing it down. I really hope that getting it all out on paper is cleasing for him.