The point is that you can just as easily flip these things around. You claim he did everything right. Maybe he did everything wrong? As you said, it's all guesswork, and there's no reason why the guesses should be in one direction or the other. GIven what we know, I think it's pretty safe to say that there were plenty of mistakes made. It might not have been a good idea to tour at all, in the long run. But, it would be weird if they didn't make any good moves, either.
I should also add that the OES tour wasn't all that long compared to what many other artists do. Proof: https://en.wikipedia.org/wiki/List_of_highest-grossing_concert_tours - so no need to exaggerate the fact that it was 14 months long (+ prep). It's actually quite common.
Maybe you live in a different country, but around here, we have many people leave their families for a few weeks at the time to go work offshore. I have yet to hear of this being an issue, simply because everything is carefully planned and the whole concept and it's potential issues (i.e. related to personal relations) are reasonably well understood. Just as you would imagine MK & crew would plan the OES tour properly, and be well aware of their own experience from the BIA tour and also the tours done by other artists (pretty sure MK is friends with some of those and would have been able to ask for advice if needed). If this indeed took it's toll on some personal relations, then that's because of bad decisions being made (at least in hindsight).
"...and things snowballed out of control." - Well, who's in charge of that, if it's true? MK, no?
That's a good question. I guess you can control a snowball, but you can't be in charge of an avalanche when it happens. You just accept it and prevent it from happening again if you get lucky enough to survive. I mean a man like MK can potentially have control over many things, but there are also financial, contractual, and psychological obligations, physical limitations, build-up of obligations, emotions, fatigue, problems with private life, family, and a million different factors.
That's why I'm trying to say MK is a human after all, and yes, mistakes are what make us humans, but it's how you react to mistakes and deal with them later on that matters. Judging by the fact we haven't heard anything from Dire Straits from 1993 (live at the BBC album released to please the contract doesn't count), and the fact the titular hero of this forum barely returns to this band in any shape or form, and that everyone agrees it's likely gone for good, he doesn't want this avalanche to repeat.
As for long tours, I still don't think it's a good idea to tour for so long. Why not do fewer shows or tours, and just spread it across a longer period? Like Bob Dylan, like Van Morrison. Mark got stuck in the album-tour formula and it's one of the major reasons he stopped touring now I think, apart from health and other concerns. Because if he releases an album, he needs to tour with as many shows as possible, it's what he has been doing for all his artistic life. Album, tour, album, tour, album, tour. And the tour has to be big because kids these days can't do it, but Mark sure can.
Sting expressed similar feelings towards large-scale tours of The Police. Marriages breaking down, tension building and spilling over the top, and band members barely surviving the experience themselves. It's all a build-up of a lot of things, I don't think anyone has ever dreamed about doing 365 shows a year. Music is not a sport, but damn, it feels like it sometimes is a sport with all this "who's bigger" attitude and measurements of revenue figures, managers and hunger for money.