Make the sauce: Combine the butter, hot sauce, maple syrup, paprika and a pinch of salt in a small microwave-safe bowl; microwave until the butter melts, about 30 seconds. Whisk to combine. Preheat a grill or grill pan to medium. Whisk the blue cheese, yogurt, lemon juice, 1 tablespoon water, 2 teaspoons of the prepared sauce and 1/4 teaspoon salt in a large bowl. Add the arugula, celery and carrots and set aside (do not toss). Brush the grill with vegetable oil. Season the salmon with salt. Grill, brushing occasionally with the sauce, until marked and just cooked through, about 4 minutes per side. Toss the salad and add salt and pepper to taste. Serve with the salmon and the remaining sauce.