Taking my gf to China, can I go to the China Embassy in Bangkok and get them both and also collect on her behalf ? Many Thanks..

I used an agent to deliver and pick-up my passport when applying for a business visa at the Chinese emabassy in BKK.

So I cannot see why you couldn't do the same.

Yes. Both Thais and foreigners can obtain visas at the Consulate / Embassy on Soi 3. Make sure to check out the visa requirements on the Embassy's website which vary on the visa type (assuming you just want a tourist visa) and nationality (they don't tell you this, but US citizens need both Form A and Form B, whereas colleagues of mine (non-US) seem to only need Form A). Also, if you are a US resident, be prepared to dish out 4500+ baht for your visa, while your Thai GF should only need to pay 1300-1500 if it is a single entry tourist visa.