And that is all I'm advocating here. If this man shows his wife an impeccable example, she may be persuaded to change herself (if she is indeed a mere harpy running down his ego for her own ends). I doubt that this man will be able to persuade her verbally, as he is convinced that his shortcomings betray a lack of maturity that is so chronic that it prevents him from fulfilling even the most minor and simple everyday tasks; he will not be able to deal with her forthrightly, as an adult, because he doesn't think he has a leg to stand on.
In order to gain that leg, my advice to him is to do things that will instill self-discipline in order to mature. At that point he might have enough self-image to give him the confidence to deal with her as an adult male. Because, at present, he's acting like a child. This post is solid evidence of it.
A man who acts like a child cannot save his marriage, and saving his marriage is the man's stated aim. He must grow up. It will take discipline to do it. He can gain discipline if he follows the advice I've given him. (He can gain it in other ways as well, and some of those ways have been posted by others on this thread.)
While I appreciate what you are saying "in principle," it ignores several variables that must also fall into place to be workable "in practice."
Your word choice is correct. My wife did have to change herself, but that self that needed changing was a free-floating miasma of self-justifying rationalizations, the only two goals of which were to provide her with a secure platform to launch speculative accusations, and using those speculative accusations to transfer responsibility to me for her lack of satisfaction in life.
Personally, I believe the grandest travesty in the Christian community in dealing with this type of problem is it's failure to recognize the enemy has been busily working on mechanisms to bypass the defenses normally confered by following Biblical principles. Much like the workings of the ACLU, People for the American Way, the Democratic party, etc., our own laws instituted to protect a way of life are being subtly shifted in their application to tear down the very way of life they were designed to protect.
When I was younger, I too agreed with my wife on why we had marital problems. It took several years for me to come to the realization that no matter how many of her hoops I jumped through, there was always something slightly wrong with the way I jumped, so my remedy was invalid. In effect, she was moving the target, then blaming me for not hitting it.
It was only when I stepped back, and acting unilaterally, informed her a carress is not "grabbing," showing frustration is not "verbal abuse," arguing for my perspective is not "demeaning her," that I was able to make her understand she did not get to define reality. Her "feelings" were subjective, and if she insisted on treating them as objective I was outta there.
The case we are currently discussing is similar in that this witch has so little wrong in her life she actually has time and temperament to threaten the marriage over the thermostat! I feel confident she was absolutely filled with joy at taking the trash out in twenty degree weather, because it gave her another cudgle to use on him, and the husband is too much the naif to recognize if she had been too sick to take out the trash, she would have been too sick to take out the trash.
If she wants to throw herself on the fire, then blame him for her burns, that's her choice. But please, don't demean the guy by trying to teach him how to keep her from throwing herself on the fire.