When it comes to Russia, take that kind of SNAFUs and multiply them by at least 20.
I have first-hand knowledge of Russia (my ex-wife and daughter live in Moscow, I have been spending time there on a regular basis between 1993 and 2019, just before the pandemic, and I know people in the Russian military). At a systemic level, what I have seen is a general culture of incompetence and corruption that pervades everything. And that was in Moscow. I don’t know (and frankly I wouldn’t like to know) how it would be in the Russian equivalent of podunkville.
My military friends there basically have told me that the situation in their military is one of constant fucking chaos and utter mismanagement. One managed to get in touch with me after the present “unpleasantness” began. He told me of his doubts about the ability of Russia to win this, and about (his words) the absolute “brothel” that every branch of the Russian military (including the nuclear forces) is.
On top of the stealing (those mega-yachts are not cheap), stealing that according to my contacts happened at all levels (from the loftiest generals to the lowest privates, most everybody regularly stole either money or stuff from the military - including several of my friends)… it would transpire that there are not a few elements in the military itself that are not happy about this whole situation and also that the morale is, generally speaking, bad - especially among the troops.
Putin has the authority to order a strike with nuclear weapons. That order has to be authorized by lower-level officers on its way to the actual launching crews. Obedience no matter what is instilled in the Russian military doctrine, of course. But there are also quite a few people in the military who would not be particularly up to the task.
Again - it is not about dismissing the threat that Putin represents. He is a dangerous MF. But it has to be put into perspective as well. No, we cannot count on one or several Petrovs that would stop that order from going through. But at the same time we know that they exist. We cannot dismiss out of hand the chances of the Russian military. But we know that the condition of the Russian military across the board is not good. We cannot forget that Russia has millions of men at its disposal. But the morale of those men tends to be bad.
We need to take everything into account if we want to assess the situation and the chances of Russia acting one way or another. I am certain that the US and NATO governments and militaries are doing precisely that, anyway.
I do not see that much wavering, and from what I hear inside Russia the sanctions are biting.
As to China, we must never forget that, first and foremost, it will act taking exclusively into account what is going to be convenient and profitable for itself.
If China ends up becoming the main provider of money and materials for Russia, even if the amounts were enough to compensate what Russia has lost (and they will not be), it is certain that the conditions China will impose on Russia in exchange are going to make Russia their bitch. There is zero love lost between those two.
Also, in any case, Russia right now does not have the capability to send oil and gas to China in the volumes that it has been sending to Europe, and it will take time and money to build that up. China could put up the money, indeed, but it will be in exchange of Russia becoming China’s bitch (see above), which is a big toad to swallow for Russia.
As the contracts for gas and oil end and are not renewed between May and the beginning of 2023 (which is the consensus here in Europe regarding what to do about it), with the Nord Stream 2 dead in the water, Russia will have trouble finding a substitute for them that will provide the amount of money that Russia used to receive.
Anyway - sorry for the wall of text. We appear to have different opinions regarding the chances of Russia doing something rash and of Russia managing to get the upper hand in this conflict. You seem to consider them to be higher than what I consider them (but of course I do most emphatically not consider them to be zero).
It is up to the strategists and analysts in the US and NATO militaries and governments to do this, they definitely are doing it, and in general they are not going to be talking about their conclusions.
We will see how it goes.