Chinese work visa. Can I have the papers/letters mailed to Japan and finish everything there?

Karen, you'd better not. It requires that the applicants should be in the country when he/she applies. Suppose there is something wrong and the consulate wants to meet you, what are you going to do? If you don't want to go to Japan, you might go to HK to apply. I heard that some foreigners applied their Z types successfully there.