Cut eggplant lengthwise into 8 (1/4-inch-thick) slices; place in an 11- x 7- x 1 1/2-inch baking dish. Combine vinegar and 2 tablespoons broth; pour over eggplant. Cover and let stand 30 minutes, turning occasionally. Remove eggplant slices from marinade, discarding any remaining marinade.
Combine chili and garlic powders in a large heavy-duty, zip-top plastic bag. Add chicken; seal bag, and shake until chicken is well coated.
Coat grill rack with cooking spray; place on grill over medium-hot coals (350° to 400°). Place chicken on rack; grill, covered, 3 minutes on each side. Place eggplant on rack; grill, covered, 2 minutes on each side. Cut chicken and eggplant into 1-inch pieces.
Cook pasta according to package directions, omitting salt and fat. Drain.
Combine pasta, eggplant, chicken, tomato, and remaining ingredients; toss well.