Cut corn kernels from cobs into a large saucepan. Using the blunt, flat side of a large knife, scrape milk and remaining pulp from cobs into saucepan. Discard cobs.
Stir in cream cheese, half-and-half, Old Bay, flour, and 1/2 teaspoon of the salt. Cook over low, stirring often, until mixture is smooth and begins to steam, about 10 minutes. Remove from heat, and cover to keep warm.
Cook sausage in a large skillet over medium until slightly crispy, 10 to 15 minutes. Remove from skillet, and drain on paper towels. Increase heat to medium-high, and add garlic to skillet; cook, stirring constantly, 1 minute. Add shrimp, Cajun seasoning, pepper, and remaining 1 teaspoon salt, and cook, stirring often, 3 minutes. Stir in lemon juice, Worcestershire sauce, and hot sauce, and cook 1 minute. Remove from heat. Add butter and parsley, and stir until butter melts.
Arrange chips on a platter, and top evenly with corn sauce, sausage, and shrimp mixture. Sprinkle evenly with scallions and jalapeño chiles.