Why do you think that it's "... unlikely even of the Chinese Communist Party losing power?"
Everything is possible but as it stands there is little likelihood of that happening. The Communist Party looks set to remain in power for the foreseeable future.
Actually a weakened Russia is very much to China's advantage because there is a long history between them
China has a balancing act to maintain. A Russia which is too weakened would pose less of a threat to Europe and that in turn might led to the Americans being able to focus less on Europe and more than China. Then there are also issues in Central Asia and the Middle East where despite Russia losing some influence; it still has influence in which the Chinese can benefit from. A weakened or unstable Russia might also not also be in a position to continue collaborating on a number of issues [military and non military] considered vital for China and might not be able to supply the long list of things China needs and can only source from Russia.
there are Russians in the west of the country who still do not like Chinese, or any other non Russians and / or non Slavics.
It's about common interests and reality; Russia's new rulers might not have a penchant for the Chinese but the reality is that China is a major economic power which shares a common border with Russia; economics plays a big part.