Some will leave and become irritants and activists. The mainland government will not like it, particularly if the people reestablish a remote Chinese government somewhere else. After all that's why mainland wants to take over Taiwan, because it has the old culture and the old enemy. First rule of war is to offer the enemy an empty victory.
It seems like the Mainland government is obsessed with Taiwan.
Taiwan's population is 23.8 million, so it would be no small evacuation. There are Chinese people living all over the world, including the U.S. - many of whom have been vocal critics of the Mainland Chinese government.
Exactly what mainland desires? I don't think its a good strategy.
Hard to say. China has a large military and all, but do they really want to go to war that badly for Taiwan? How many casualties are they willing to incur to conquer Taiwan, and would they continue to have the support of the people if they see their loved ones coming home in body bags? The Soviets got bruised and bloodied when they tried to take over a much smaller Finland.
There's also a matter of being able to keep Taiwan under control, assuming that they're successful in conquering it.
Yes, and they should be at the table when decisions are made about what is to be done. Perhaps they wish to unify. I think that would (militarily) be smart. As mere allies they are not terribly strong, but if they were to form a union they would be another world power, and I think they could do so.
It would be interesting if they did. Maybe they could revive SEATO or form some similar alliance. Or maybe just expand NATO into a global alliance. Originally, CENTO and SEATO were established with similar goals as NATO. There's also the OAS. We could conceivably form a massive worldwide alliance that could stand up to China.
Russia and US may spat but are brothers. I would suppose Russia might try to use it to gain advantage of some kind but is not interested in destroying us outright. Another thing is Russia may do some distraction or try to gain diplomatic gains in trade with China, so that is another thing to consider. We actually had an entire cold war with the USSR and didn't destroy each other. That is brotherhood.
Well, all three countries have had their ins and outs with each other. Russia vs. China, China vs. America, Russia vs. America - all at various times. Although we were all allies during WW2, more or less. It was a bit complicated with China at war with Japan (but not with Germany) and Russia at war with Germany (but not with Japan, not until the very end). But they still remember that, and that may have been a key factor in our not going to war with each other. There was a brief period when we were the sole possessor of atomic weaponry, and we could have brought down a world of hurt upon Russia or China, but we didn't. Patton and MacArthur wanted to do that, but they were overruled.