American Working in Korea Applying for Visa to China

I will be going to China sometime around June 20 of this year for a visit. I noticed on a website the following:

Foreigners who want to apply for visas to China, he/she must provide the alien registration card in South Korea with at least 6 months remaining validity. Diplomatic and Official/Service passport holders are excluded.

I currently am residing and working in South Korea. My current alien registration card will expire this coming August which is less than the 6 months which is stated in the above. Will you please let me know what I will need to do?

Also, I going to China for a new position I have accepted in Shanghai. My future employer told me that I will obtain the L Visa and arrive in Shanghai and then a Resident Visa will be obtain. Therefore, I will not have a round-trip plane ticket since I am not returning to South Korea.