Add half of tomatoes to a large saucepan filled with boiling water; cook 20 seconds. Plunge into a large bowl of ice water. Repeat procedure with remaining tomatoes. Drain. Remove tomato skins; discard. Halve tomatoes; scoop out seeds with a slotted spoon, and discard. Coarsely chop tomatoes.
Heat 6 tablespoons oil in a large Dutch oven over medium-high heat. Add onion, carrot, and celery; sauté 5 minutes. Add garlic; reduce heat, and cook 15 minutes. Stir in tomato paste; cook 1 1/2 minutes. Add wine; cook 10 minutes. Add tomatoes, basil, 1/2 teaspoon salt, and crushed red pepper; simmer 1 hour or until reduced to 7 1/2 cups. Reserve 5 cups sauce for Open-Faced Meatball Subs and Creole Shrimp and Okra.
Cut 3 slits into the skin side of each fillet. Heat 1 tablespoon oil in a large skillet over high heat. Sprinkle fillets with 1/4 teaspoon salt and 1/4 teaspoon black pepper. Add fillets, skin side down, to pan; cook 4 minutes. Turn and cook 1 minute. Remove from pan. Add remaining 2 1/2 cups tomato sauce, 2 tablespoons oregano, and chile to pan. Add fillets, skin side up, to pan. Cover; cook 3 minutes.
Heat remaining 1 tablespoon oil a skillet over high heat. Add squashes and bell pepper; cook 3 minutes. Stir in remaining salt, remaining black pepper, remaining oregano, olives, and capers. Serve with fillets and sauce.