Ok, this is a total noob question that I should know the answer to but I never book legs of flights seperately so I want to make sure of things before I book my flight so I give myself enough time.

Situation is I booked a rewards flight awhile ago through BA on Cathay Pacific to fly from Chicago to Hong Kong.
I now need to get from Pittsburgh to Chicago that day and am looking to book a flight on AA.

Question then is, upon checking in with AA in Pittsburgh will my bags be checked all the way through to HKG or will I have to recheck them.
And can I get the boarding passes all printed at PGH for all the flights as well.

I ask because my choices out of PGH either result in an hr and 15mins layover time in Chicago or 6hrs & I want to make sure I have time to do what I need to do for the connection.

Anything else I should be aware of?
Thanks in advance.