Titan, 3 answers
1) Coal fired power stations are indeed a major source of pollution in china. But light manufacturing is not energy intensive. Countless millions of air-cons, fridges and TVs in Shenzhen and Guangzhou are more to blame. Which is a shame because the factories are steadily moving inland in search of cheaper land and labour. The cities will only grow.
2) It doesn't fail often, which is ironically not such a good thing as diesel powered generators are generally less polluting than the power stations.
3) The dormitories i've seen are not squalid, and if necessary heated by electric fan heaters. A fire in the room would be a sacking offense - dead workers is bad
PR, causes problems with the authorities and delays production. The workers eat in the canteen. They use gas to cook and the food is usually not bad.