Also, we heard the same doom and gloom about the break-up of the Soviets...many nuclear armed rogue nations and such...didn't transpire. There are a LOT less nucs in China than the Soviets had, so excuse me if I discount this arguement.
If there is a revolt...a strong nation will rise out of the rest with our and the ROC's help and we shall work with them, like we did the Soviets, to avoid unchecked proliferation.
Of course, the current trade situation is unfair for us.
As to the nuclear weapons, it's hard to predict the future, one can never know who will get their hands on the weapons.
Of all the scenarios, IMO, slowly creating a democratic China, similiar to what happened to ROC on Taiwan, is the best way.