Bring a large pot of salted water to a boil. Add the pasta and cook according to the package directions until tender. Drain the pasta, rinse it under cold water, and set it aside to cool completely.

Pat the shrimp dry with paper towels. Add the shrimp to a bowl with olive oil, Cajun seasoning, smoked paprika, and garlic powder. Toss until the shrimp is fully coated.

Heat a skillet over medium-high heat. Add the shrimp and cook for 2 to 3 minutes per side, or until the shrimp are pink, firm, and cooked through. Remove from the heat and let the shrimp cool. Once cooled, roughly chop the shrimp, leaving a few whole pieces for garnish if desired.

Slice the hard-boiled eggs in half. Remove the yolks and place them in a mixing bowl. Chop the egg whites and set them aside.

Mash the egg yolks with a fork until smooth. Add the mayonnaise, yellow mustard, Dijon mustard, sweet relish, pickle juice or lemon juice, hot sauce, Cajun seasoning, garlic powder, onion powder, smoked paprika, salt, and black pepper. Mix until creamy and well combined.

In a large bowl, combine the cooled pasta, chopped shrimp, chopped egg whites, celery, red onion, red bell pepper, green onions, and parsley. Pour the deviled egg dressing over the top and gently fold everything together until the pasta salad is fully coated.

Taste and adjust the seasoning if needed. Cover and refrigerate for at least 1 hour before serving so the flavors can come together.

Before serving, stir the pasta salad again. Garnish with smoked paprika, green onions, parsley, and any reserved shrimp.