We discussed Odessa a bit above. I believe that's gonna be one of the most risky parts of the entire invasion. If it goes just mildly wrong, they'll be relying on paras/specials alone until the ships can turn around and bring some more BTG's. A lot depends on how brutally Ukraine actually try to defend. If they deploy SAM's (and not just MANPADS there) its gonna be an absolute bloodbath, no matter who wins.
They would, but they'd simply crush them like they did to Hong Kong, where everybody hates them but are powerless. You could be right of course, and the leadership might genuinely think that political pressure might lead to reuinification. I don't know all that much about modern China honestly.
True, and there will be the issue of civilian deaths that will play into Putin's appetite. Not that he cares about civilian deaths, but he will care about international perceptions of mass casualties, which unlike Crimea and Donbas, he won't be able to shut down media reports and cell phone footage.