As for the distance it was felt; I don't know anything about China but assume that it will transmit shaking better than would be the case in California, where the crust is so beat up. It has been well-known that mid Continent quakes like New Madrid area (or, say, the M5.2 a couple weeks ago) are felt over a wider area.

As for the long historical record, yes, this is of interest. HW was involved in working on the North Anatolian fault near Istanbul and her group looked into this to some extent. HW is funded with others to work on North China quakes/paleo-seismology and historic record will certainly come up.
Chris