Everything you've listed sounds good.
You may want a neck pouch for your papers/passport. Some people like a fanny pack with a steel cable in the waist band to keep papers close at hand. Be VERY careful if you take the fanny pack off in the bathroom or on the plane. I've seen more than one travel companion lose things that way.
+1 on the small compass. Coming out of subway stations in Korea taught me that one.
A little mini squeeze light around the neck is handy and can be combined with the above compass. I've also got a whistle on mine neck lanyard. I hear street crime in China isn't bad, but you never know...
I'd bring the Imodium AD, but if your MD has something better that he can Rx you, go for it. A decongestant is good. Perhaps something for allergies.
Sun screen, chapstick, and hand cream.
A card with the name and address (in Chinese) of where you're staying is excellent. Also add to it phone numbers and email addr's of contacts. Giving a copy of your list of your contacts to someone stateside as well as your itinerary is a good idea.
Photocopy all your credit cards, passport, etc. Take a set of the copies with you (stored separately from the originals), and leave a second copy with someone stateside that you can contact in an emergency.
In addition to TP, a small bar of soap in a baggie. Maybe china is as modern as they say, but I've found having my own soap and TP handy. I can use a bandanna as a hand towel. I actually bring two bandannas: one "dirty" and one "clean" that I can use for differing applications.
Spare pair of eyeglasses if you wear 'em. If you wear contacts, having a pair of eyeglasses along as a backup is a good idea.
Sleeping pills. Possibly controversial, but I've found them useful.
Soft foam ear plugs. Different societies have different standards for "acceptable noise." I like the conical-shaped ones; the cylindrical ones hurt my ears. Could be a problem if you can't hear a fire alarm, but I've used them a lot on buses and trains and such.
Eye shades and small inflatable pillow. Not essentials to be sure, but a little sleep can be a godsend. I have no affiliation with REI, but I've used and like:
http://www.rei.com/product/763637Don't know your exact circumstances, but one of those little immersion heaters can be nice provided that you can get the appropriate electrical converter. Speaking of which, check on the electricity where you'll be going in terms of voltages and such. The ability to recharge cameras, shavers, cell phones, lap tops, etc. isn't a given.
+1 on something in the Ibuprofen (Advil) class although I prefer Naproxen Sodium (Aleve). Aleve lasts 12 hours whereas Advil lasts 6. If I really have an achy back, sore knee or what have you, I can take two tablets before bed and have the anti-inflammatory properties carry on all night.
Clothesline. In humid climates, sometimes having some clothesline so that you can dry things out is invaluable, although maybe not as important if you're going in December. Still, sometimes it's nice to be able to "rinse and wring" and hang socks and such to dry. A small travel shampoo sized bottle of detergent can be handy.
Whatever maps and guidebooks that you can get here that are good.
Sometimes it's good to have enough money in the local currency on hand before you hit the ground that you can buy a snack or pay cab fare. It's worth researching where to get the best exchange rate (your credit card, an in-country bank, your hotel, airport exchange, etc.). In Japan, the post office was really good.
Bug juice. Sounds like you won't need it, but you never know. I've been caught w/o it and regretted it.
Just some thoughts.