Oops... I forgot! For killer Texas BBQ you gotta go to Casey's which is on the northwest corner of Nakoma and 281 (right by the approach for SAT Runways 12L and 12R - the big jets use 12R). I miss chowing down on some killer breakfast tacos (a San Antonio staple unheard of in Dallas). See if you can find the folding chair where former President Clinton sat down in on a visit to San Antonio some years ago (hint: it's the one that has a sticker with the Presidential seal). There is another Casey's on I-10 but I don't know exactly where.
You're right, Lifesaver... the Riverwalk is too touristy and most locals don't usually go there unless entertaining friends from out of town. I didn't go there much.
And don't forget Dick's Last Resort on the Riverwalk... rowdy, the service is intentionally surly (but not rude) but the food's good! After all 'you can't kill a man born to hang!' Get yourselves a 'Big-A** Beer' mug -- or better yet, sneak one out!