PEK-HKG is not a domestic flight (related to politics, where Taiwan, Macau and Hong Kong flights are considered International).

All of the aircraft Air China operates on this route feature IFE, but it depends on whether its an overhead TV screen (A321) or personal TV with AVOD (with the occasional A330s flying this route).

There will be complimentary hot meals served, with 2 rounds of drinks and if I remember correctly, it will be the usual beef or chicken rice / noodles but it really isn't that bad. In Asia, most if not all full-service airlines serve meals (even for a one-hour HKG-TPE flight with CI, there are hot meals) unlike their European or American counterparts.