1- The problem is who they see is their biggest threat now? Does antagonizing China help them to contain Russia? And money is not unlimited, the Europeans cannot keep their social warfare and at the same time spending to contain China and Russia at the same time, they will have to choose.I don't think this is the case in the long term.
1) Europe will rearm for sure and be fully aligned with the U.S.
2) Belt and Road is probably dead in Europe, hopefully they can salvage some of it but I don't see how.
3) Performance of Russia's conventional military hasn't been the best, it would degrade European and U.S. perception of their capabilities. Which would in turn lead to
4) U.S. will be able to focus more on the Indo-Pacific.
Comparison with 9/11 is not appropriate since Al-Queda and Taliba were NOT a part of the Chinese camp, but the Russians are.
2- That is to been seem, the European economy is not in the best shape, so rejecting a market of the size of China to offset the lost of the Russian market could be a not very good idea.
3-Regardless of the Ukrainian twitter victories, the Russians are hammering that country to the point that their president is begging the Chinese to make it stop and NATO can do nothing without starting nuclear exchange, If there is a lesson for the Chinese is that their nuclear arsenal is maybe too small.
4-Yes, there is not illusion the for U.S. they see China as their long term threat and they will keep their focus in the pacific with or without Europe but an isolated Russia could derail that. Iran having a nuke sounds like very big problem for the U.S. far bigger than China in the short term.