There is a lot of value there, especially in Taiwan, whom China already believes is theirs.
No. The dynamic between Russia/Ukraine/Crimea is
completely different from that of China/Taiwan.
China/Taiwan split because of a bloody civil war, so it is more like North and South Korea. Taiwan is armed to the teeth (with modern Western hardware) and is always-vigilant about a Chinese invasion, which must cross a good stretch of sea. Taiwan is rich, prosperous, and has a large, well-funded, well-trained military, unlike Ukraine. Their military is larger than that of the UK or France. There are active military agreements with Taiwan and the US that Ukraine doesn't have. There isn't a backdoor into Taiwan in the form of a Chinese naval base. Crimea already had partial independence (its status was that of an autonomous region), so Ukraine's power in Crimea was limited to start with, and Crimea's local government was enthusiastically in favor of the break and annexation (it kinda helps when the locals don't view the invaders as invaders, ya know?).
And China has
always maintained the Taiwanese government as illegitimate and that it is the rightful ruler of Taiwan, and Taiwan's government views itself as the rightful ruler of China, so these claims and legal arguments aren't novel and Russia's use of them isn't going to change anything here.
The West would
much more forcefully respond to Taiwan than to Crimea. First, because the Crimean invasion happened with virtually no shots fired (except for a few isolated cases) and with the Crimeans welcoming the Russians, who were relatively low in number (measured in thousands or tens of thousands), whereas a Taiwanese invasion would necessarily have to be the guns-blazing, missiles-flying, type with lots of violence, and a huge number of troops (China would need at least a few hundred thousand). Taiwan
can defend itself, and it's
willing to defend itself, unlike the Crimeans, who weren't willing and couldn't even if they wanted to. Second, because there are military agreements in place. Ukraine isn't a member of the EU, nor is it a member of NATO. If Russia invades a NATO country and NATO twiddles its fingers (which would be unthinkable),
then we can talk about this being applicable to Taiwan. Third, Taiwan matters. Economically, Ukraine is footnote. Taiwan's economic role in the world is much larger (e.g., TSMC), so there would be far, far, more at stake.
Crimea is a unique case that really isn't applicable anywhere else in the world.