I'd say there's a good chance you'll be able to buy your way to a top score while the poor become the geocities of citizens.
> "Diaper stuffing" while humourus is probably not far off the initial reputation optimization schemes that have probably already commenced.
The government would keep the algorithm a secret, so there would be a SEO for human beings: the CRO citizen ranking optimization. CRO would tell you what books to buy, the top 10 items to boost your rating, what people you should befriend...
This is a country that imposes the death penalty for corruption. Social hacking isn't something that is going to happen there.
1. That death penalty is an effective deterrent.
2. That social hacking would be tried as corruption, or even at a level of corruption for the death penalty.
3. That China doesn't have a corruption problem already regardless of the potential penalty.
http://en.wikipedia.org/wiki/Corruption_in_China (not saying this is the truth, just that you're making an assumption that not everyone agrees with)