Guangzhou is one of the safest cities I've been to. We walk the streets at night in a loose group, usually around the Beijing Pedestrian Street area (北京路), and never once feared for our safety. There isn't bands of pickpockets roving around the metro stations like in Rome, and Guangzhou's tourist attractions are free of scammers common in other cities.  That said, it doesn't hurt to be wary of non-violent...