I think Nicholas's situation was very simple. He was just totally overwhelmed with everything, and so stressed out by all the responsibility that he could not cope. He inherited his situation very early on in life, so was thrown into the melee inwillingly. He did not have the time to mature as a human being in an extraordinary situation, or develop the necessary people skills to handle his demanding uncles, and the advisors inherited from his fathers court. I think they expected him to react like his father to various situations, which of course he did not.
When we are totally overwhelmed by a situation, our coping skills deminish and we seek to escape, in some form or other.
I think this is why he loved walking and the outdoors so much. It afforded him the opportunity to escape from all those oppressing people.
My opinion is that Nicholas sufferred from severe stress and anxiety, and certainly not autism. Depression maybe, which in its worst form makes one incapable to a certain degree of doing the smallest things in life ( like making decisions). However many people who suffer from depression, are able to go out into the world and be absolutely charming and perform wonders around other people, but minutes later recede back into the gloom.
I work in an extremely stressful situation as well, and have to " juggle" people and situations all the time. I also sometimes find myself " listening" to people but not "hearing" a word they are saying. It happens sometimes that ones brain shuts down for a while, simply because we can only cope with so much at a time. I personally think he suffered from traumatic stress disorder, and depression. Perhaps his brain was just shutting down temporarily. The corporate world we live in today causes exactly the same problem for many people.
I think he built a shell around himself, as a way of protecting himself from his situation, and withdrew into his own world. This would also explain his fatalistic view of life towards the end. His outlook and that of his wife was " Its Gods Will" ,or " We are in Gods hands" Which is of course true. But one also has to do something about your situation, and cannot let events just carry you along. And I think this is what he did towards the end. Everything became just too much. His wife wore the pants, so to speak, and manipulated him emotionally right from the beginning.
I dont think that his wife was any help either, and if she was as intelligent as people say she was, she would not have made so many successive, repetitive mistakes. Intelligent people take advice from other people, and she recieved an enormous amount from everyone after he left for Stavka, and stupidlyand blatantly ignored everyone, to the point of alienating her family. So did he actually. So many chances were lost to save the situation.
One can go on and on ........