foreigners subject to laws of land (Guangzhou)

When living and working in China how are foreigners (usa) subject to general laws and basic human rights. I have been readiing online two different views. Either there is no freedom of expression at all. One has to hide or dissappears or people (chinese or foreigners) are free to express just dont talk publicly negative about laws you dont like. What are the realities of living in China. I understand their government is comunist/socialist yet its quite different than N.K. and former USSR.
I take it one can live and breath rather happily as you are all there.

I have not yet arrived as i am continuing with and finishing my training.

Assistance Guidance Understanding of culture would be helpful.