hi st
I am staying in Dongguan, like you, because my husband is working in Dongguan. I went there 1 years ago when my bb was half year old. I think you need to bring along the milk powder. Find a good water filter to be installed. :)
about safety,
(1) dont talk mobile on the street, when it rings on the street, let is ring or find a supermarket or safe shop
(2) be careful about motorcyclist passing-by you
(3) do not bring handbag if possible.