Some see this development as a major advance for China, but it’s hard to understand why. The Chinese bombers located on these islands would be used only in the case of war. And if a war does break out, these islands would be turned into craters.
Yes. Unless China shoots or starts to forcibly stop ships from moving through the South China Sea without Chinese permission, these assets don't change anything about legal control.
If shooting starts, all the assets and allies come into play.
Not that the island bases are irrelevant. It depends on what is sent against them. Absent America, China could use the bases against other opponents.
But they do not make a decisive contribution to who would control the South China Sea in a shooting war that involves America.
Honestly, I'm still wondering how the artificial islands would handle a typhoon, as I noted here as an aside.