Bring water and 1 teaspoon salt to a boil in medium saucepan. Place couscous in large bowl. Pour boiling water over couscous. Cover bowl with plastic wrap. Let stand 5 minutes or until water is absorbed. Fluff with fork. Cool to room temperature. [To cool quickly, spread couscous in thin layer on baking sheet or platter.]
Add cucumber, poblano pepper, avocados, bell pepper, olives and cilantro to couscous. Whisk oil, lime peel, lime juice, red pepper flakes and remaining 1 teaspoon salt in small bowl. Pour over food; stir gently to blend. Stir in shrimp. Serve immediately or refrigerate 2 hours before serving. Taste and adjust salt and lime juice before serving.
