I can't speak to a comparison with Chinese cities, but TJ is pretty safe, as there are hundreds of thousands of middle class people living there now. Just stick to the places they go to (Zona Rio, Agua Caliente, etc) and you can have a nice evening out for 1/2-1/4 what you would spend in San Diego.

I believe there are also 1-2 startup incubators (space only, no money to invest) in Zona Rio now.