One World is a useless alliance for purely domestic China travel. However, if you look for and book in the right places with the right timing, flights are often cheap enough inside China that you might not get good value from your miles anyway.

Seems to me that the best way to play this would be:
--Home-CTU (via HKG connection) using miles
--CTU-CSX (nonstop, domestic paid ticket booked online in mid-October for November travel, should be able to get for around RMB 800 all-in)
--Changsha-Guangzhou via bullet train, RMB 504 1st class/RMB 314 2nd class seat *
--Guangzhou-Hong Kong intercity train, about RMB 150 standard seat.
--HKG-Home using miles.

* This journey on G train is only 2.5-2.75 hours depending on departure selected. Since the security and boarding procedures are more streamlined and you don't have to wait for bag claim on the arrival end, it actually ends up faster in elapsed time than the plane sequence, and with next to no risk of delay due to ATC, WX, or MX factors.