Are the sedevacantists "One, Holy, Catholic, and Apostolic?" Are the sedevacantists infallible and indefectible and do they have authority from God? The Church is supposed to be all of these things but I do not see it in the sedevacantists. I think they have a point when they say the Novus Ordo might not be the Church, but I don't think they can reasonably argue that they are the Church either if they honestly look at the sedevacantists with the same scrutiny they look at the Novus Ordo. And I think it absurd to claim that the Church can go on for generations with no pope and no way of ever getting another pope without divine intervention, though sedeprivationism does not have this problem because in that system the Novus Ordo pope could convert and become the true Pope. And I see a big contradiction when they say the Church is indefectible, but they basically all believe that the Church defected and became a false sect and that now we can no longer follow it but instead we have to follow a few dozen self-appointed men who might have valid orders but were never sent by the Church. Sure some of them try to save indefectibility by claiming there is one or two faithful Bishops who have not defected but none of them can name them and none of them follow them. I do not know which position is right and I see problems with all of the positions so it is a mystery to me. I don't have the answers either but as far as I can tell, neither do you, you just claim to.
If I had to guess what the truth of the matter was I would guess there is a true Pope in hiding, but there are problems with that as well.
First, St. Athanasius was quoted as saying, "
Even if Catholics faithful to Tradition are reduced to a handful, they are the ones who are the true Church of Jesus Christ." Scripture also is very clear in stating that the path to heaven is narrow, and few find it. These are things we must keep in mind - only the minority will hold the truth.
We should also remember the Catholic Church is ONE in doctrine, so for example, the SSPX and the sedevacantist positions both cannot be right at the same time.
You give many examples of problems that exist with the groups today. This is EXPECTED. If you were alive 2000 years ago and witnessed Judas betray Jesus and St. Peter deny Him 3 times, would you say Jesus and His Apostles didn't hold the truth because they had problems? Of course not.
The bottom line again is that there MUST be one group, no matter how small, that is the true church. You obviously need to make a decision ASAP on which one it is. You need to rethink the discrepancies you have for each group - you are obviously mistaken on one of them.