Cook pasta in a large saucepan of boiling salted water, following packet directions until al dente. Drain. Refresh under cold running water. Drain well. Transfer to a large bowl.
Meanwhile, preheat a barbecue or chargrill on medium-high. Combine zucchini, oregano and 2 teaspoons oil in a bowl. Season. Cook, gently tossing, for 3 minutes or until lightly charred.
Place lamb and pan juices in a heatproof bowl. Microwave on High for 1-2 minutes or until warmed through.
To make the dressing, combine the vinegar, capers, lemon rind, 2 tablespoons lemon juice and the remaining oil in a bowl. Season.
Coarsely chop half the herbs. Add all herbs, lamb mixture, onion, zucchini, half the dressing and half the fetta to the pasta. Toss to combine. Transfer to a serving bowl. Sprinkle with remaining fetta and drizzle with the remaining dressing.