Answers to your questions:
1 There is one office in Scarborough Town cener. If it is too far for you, you can go to where you apply for your SIN card and ask them (most probably there is one in the same building).
2 I suggest you not take the risk. Because "an interview may be required". Even if they don't require an interview, what will happen to your application if they find out you've left Canada?
Where are you going? Do you have the website of Canadian Embassy in Beijing?