Thai citizen with Schengen visa to China for tourism

I am a Thai citizen, currently holding Schengen Visa. I'll be travelling on Tran-Siberian train through China in May. I have some questions here:

1) Can I apply for China Tourist L in Barcelona instead of Madrid?
2) How long does it take from making an appointment to final approval?
3) If I can't pick up the result myself, can it be shipped by post to other European country?