Boil the corn in salted water for 8 to 10 minutes until tender; cool slightly before cutting kernels off the cob.
Dice avocados into 1/2-inch cubes, finely dice red onion, halve or quarter cherry tomatoes, and chop cilantro while the corn cooks.
Preheat the grill to medium-high heat and prepare 4 skewers.
In a bowl, whisk together mayonnaise, sriracha, 2 tablespoons lime juice, and 1/4 teaspoon salt to make spicy mayo.
Combine cooled corn kernels, avocado, cilantro, red onion, 2 tablespoons lime juice, olive oil, salt, pepper, and queso fresco; gently toss and set aside.
Pat shrimp dry, thread evenly onto skewers, and coat with a mixture of vegetable oil, 1 1/4 teaspoons salt, and smoked paprika.
Grill shrimp skewers for 2 minutes without moving to develop char; flip and brush with barbecue sauce.
Grill another 1 to 2 minutes, flip again, brush with barbecue sauce, and grill a final 1 to 2 minutes until shrimp are cooked through.
Prepare couscous according to package instructions and fluff with a fork.
Divide couscous evenly into 4 bowls, top each with a shrimp skewer, corn salad, and cherry tomatoes.
Drizzle spicy mayo over each bowl, garnish with fresh cilantro, and serve with lime wedges.