No worries Dom.
If it helps, crap pay for a 737 FO is around 37K/month and good pay for a 320 FO 56K/month, just as a yardstick.
12K will get you a new(ish ) 3 bed 2 bath in TC with 1200' ( actually closer to 1000' actual ) living area.
Yep, the pollution sucks, but I guess you cant have everything
Have spoken to many expats who have lived here for 15-20 years and showing no ill effects, although they say the smog has deteriorated in the past 5 years,\. Of course, everyone will react differently.
Cheers