China Visa & Flights

I need to apply for a visa too visit China so checked the embassy website and found this... "For a tourist applicant, in principle he shall evidence his financial capability of covering the travelling expenses in China, and when necessary, provide the air, train or ship tickets to the heading country/region after leaving China.".

Does anyone know what "when necessary" means in this context? I'd rather get the visa before paying for flights and hotels just in case it's refused for some reason.

Also, my gf found some info saying that the background of the photo needs to be blue. Is this true?

Is there likely to be any problem for a Thai citizen getting a visa for China? How much money do they need to show in the bank and how long does it have to have been there.

Also, is it likely that a travel agent in Chinatown will have better flight deals than the internet? If so, do you know of any good travel agents in that area?