Make this salad into a main-dish by adding grilled eggplant, chicken, or steak. If you use eggplant, slice it, salt it, and let it stand for a few hours to release excess liquid before seasoning and grilling.
Cook pasta until tender according to package directions. Drain and rinse with cold water; transfer to a large salad bowl.
Meanwhile, in a small bowl combine vinegar, oregano, marjoram, garlic, lemon zest, salt, and black pepper. Whisk in olive oil. Add half of the mixture to the pasta; toss to coat. Add the tomatoes, chickpeas (if using), bell pepper, feta, onion, and cucumber to the pasta mixture; toss to coat. Cover and chill until serving time.
For dressing, whisk the yogurt into the remaining vinegar mixture. Season to taste with additional salt and black pepper. Chill until serving time.
To serve, add the lettuce to the pasta mixture in the salad bowl; toss gently until evenly combined. Top with chopped grilled eggplant, chicken, or steak.