In a 5- to 6-quart pan over high heat, bring 2 1/2 to 3 quarts water to a boil. Add shrimp and cook for 1 minute. Add scallops, cover tightly, and remove pan from heat. Let stand until shrimp and scallops are barely opaque but still moist-looking in center of thickest part (cut to test), 2 to 3 minutes. Drain and rinse in cold water until cool.
Meanwhile, peel and pit mango. Slice fruit lengthwise about 1/2 inch thick. Coarsely chop enough of the scraps to make 1/2 cup. In a blender or food processor, whirl chopped mango, oil, lime juice, cumin, ginger, cinnamon, and garlic until smooth. Add 1/2 teaspoon hot sauce and 1/2 teaspoon salt; taste, and add more hot sauce and salt if desired.
Peel and pit avocado. Slice lengthwise about 1/2 inch thick.
In a large bowl, gently mix shrimp and scallops, mango dressing, salad mix, and mango slices. Mound equal portions on four dinner plates. Garnish with avocado slices and taro chips. Add salt to taste.