Exactly, Putin is not the grand strategist the world thinks he is
Chances are the invasion on the northern and eastern fronts are more or less feints, and only the southern front actually matters to him, as it gets him full control of the Black Sea shore and the oil fields. He needs the Ukrainian forces fully occupied elsewhere, and doesn't much care what happens there as long as it absorbs enough of their attention.
China will probably prop Russia up 1) It will get Oil and Gas cheaper 2) A mean Russia keeps the West from picking on China. 3) Russia has a lot of nukes and making it crazy helps nobody.
There's only one way for him out now, and it doesn't involve him being alive. It's only a matter of time at this point.
What way is that? Because I think the one he's banking on is victory in the war over the next four weeks.
Russia will suffer greatly under sanctions, but that itself is unlikely to bring him under.
The Hitler 1945 option.
The other enlightening book is https://en.wikipedia.org/wiki/Stalingrad_(Beevor_book) which shows just how truly absurd the war between Germany and Russia was and how megalomaniacal the leaders of those countries were.