"Skylink" will move you quickly enough, if you've figured out where you are, where the nearest station is, and where you're going (easy since AA's FA's usually read off connecting gates during descent or taxi time, and the AA magazine has a decipherable diagram). The longest walk comes up when your flight arrives at a low # A or C gate and departs from a high # gate in the same terminal. Low C to High A, walk, but almost anything else ride.

Bags, even given the long distances involved, for some reason AA's DFW baggage transfer system seems to have worked for me for nearly four decades and many alterations to facilities. I've had 45 minute connection out to the old "Tin Barn" and seen my bags being loaded aboard the SAAB. SAT's a not very busy small airport, not far from Downtown, and frequernt flights from DFW have always seemed to get friends/fellow travelers expedited delivery of late bags.

I wouldn't worry unless you're on the last flight of the night with a SAT connection.