Any Chinese plan to invade Taiwan would probably ignore the Kinmen and Matsu islands. But a group of larger islands, the Pescadores, are within artillery range of Taiwan itself. The Pescadores have an area of only 127 square kilometers, and a population of 90,000. There is a military garrison on the island, which includes an armored brigade, lots of infantry, anti-aircraft missiles and mobile anti-ship missile units. The Pescadores are doubly important, as they are opposite the most important landing beaches on Taiwan. Any invasion force must seize a port as soon as possible, in order to bring in more troops and supplies. You don’t have much chance of conquering the island until you’ve done that. The two best landing are areas, for seizing nearby ports, are in the northwest and southwest regions of Taiwan. The better of the two is in the southwest, where the ports of Kaohsiung and Tsinan are near the landing beaches. Those beaches are also near the Pescadores islands.
If China uses some of its airborne and amphibious forces to take the Pescadores, they will have a base for the next stage of the operation; the landing on Taiwan itself. But it is likely that speed will be the most important element. The faster the Chinese establish themselves on Taiwan, the better their bargaining position with the United States, and the rest of the world.
I agree that the islands close to the mainland will be bypassed and isolated.
I tend to think that the northwest approach is more likely as a more direct effort to bounce Taipei. And I think that the ports would be the initial targets rather than a secondary one after hitting the beaches.
But the Pescadores would be important to secure to spread out the Taiwanese by providing a staging area for secondary attacks (that could become serious if not defeated or contained by Taiwanese defenders).
Speed is key. If China takes too long, Taiwan can mobilize and America and Japan can decide to interven and reach the theater in time to defeat the Chinese. Which is why a one-dimensional missile bombardment or a blockade of Taiwan will never be the military action of choice for Peking if they want a military solution to their "Taiwan problem" (although if justice is high on your list of priorities, the situation should be called Taiwan's "China problem").
Although there is a scenario for the Chinese picking solely on Taiwan's islands.
