Applying visa in brisbane, but leaving from Melbourne

It's ok that you apply for the visa in Brisbane but leave from Melbourne if only your living place if under the consular Jurisdiction of Brisbane. You do have to have an itinerary when applying for the visa, since I find that there are blanks about this in the visa application form. And you need the roun-trip air ticket as the application documents.
For visiting family in Shanghai, you also need othe documents besides the round-trip air ticket, including your valid passport, a fully filled visa application form stuck with a passport size photo, invitation letter from your family in Shanghai and copies of your family's passport, valid residence permit in Shanghai, proof of your relationship such as marriage certificate or birth certificate.