Mmm, I don't see how the historical context for the conflict is relevant

> 4 Eastern Oblasts that voted to secede from Ukraine

I mean.. "lol"

Most importantly for the current topic, there is no international mechanism for regions to legally secede. This is basically "not okay". China can't possibly approve of that. The whole Chinese claim to Taiwan rests on that not being okay.

Your first point makes more sense. Maybe the goal is tieing up Europe with an idiotic conflict? But they undermine themselves and don't really win much of anything