Meh. The one-child problem isn't as big as it's made out to be for two major reasons: the growing middle-class in China and good, old-fashioned local corruption.
Contrary to popular depictions, forced abortion is not the rule for 2nd, 3rd, etc. children. Instead, it's a steep fine that the family has to pay (about $5000 last time I checked). When the family is rural and poor, the fine is insurmountable and abortions take place.
When the family is urban and well-off, $5K may be a reasonable price to pay for a young couple who wants a 2nd child. Alternately, with the right bribes and/or guanxi (roughly translated as "connections/favors"), local officials can be persuaded not to report the birth.
The male/female thing is a major problem, but as the demographic pressure on young males increases, I think you'll see the stigma of a non-Chinese wife decrease. To put it another way, a half-Chinese grandchild is better than no grandchild at all.
As to the problem of supporting the elderly...well, let's just say the iron rice bowl has a lot of holes in it. Nikov, you said it yourself...they're a state capitalist system, not a Communist one. It's sadly ironic that the Chinese Communist Party now regularly sides with businesses against workers and quashes attempts by labor to self-organize.