U.K. citizen holding a Korean E2 visa

Hello, I intend to travel to China on August 7th 2013.

I am from the U.K. and work in Korea. My E2 expires September 25th 2013.

Although I will be extending it (as I will be working here for another year), my ARC card may not be renewed in time for me to apply (with the renewed ARC).

Can I apply with my current ARC which expires in September?

I am also going back to the U.K. for a 2 week holiday in June, should I get one there?

Please advise, I'm not sure what to do as my trip occurs so close to the renewal of my contract at my school.

Many thanks
Sam