To prepare salad, combine first 6 ingredients in a large bowl.
Bring 5 cups water to a boil in a large saucepan. Add shrimp to pan; reduce heat, and simmer 2 minutes or until done. Drain and rinse shrimp under cold water; drain well. Cut shrimp in half lengthwise; add shrimp to sprouts mixture, tossing to combine.
To prepare dressing, combine sugar and next 4 ingredients (through chiles) in a small bowl, stirring with a whisk until sugar dissolves. Pour dressing over salad, tossing to coat. Sprinkle with peanuts. Serve with lime wedges, if desired.