Toss shrimp with olive oil, garlic, smoked paprika, cumin, chili powder, salt, pepper, cayenne, and lime zest. Marinate at room temperature for 15 minutes.
Combine pineapple, red onion, jalapeño, and cilantro. Add lime juice, lime zest, and salt. Toss and set aside to meld.
Stir together sour cream, lime juice, lime zest, garlic, salt, and water until drizzleable. Set aside.
Prepare cabbage, avocado, and remaining toppings and arrange on the table.
Heat grill or grill pan to high. Oil lightly. Thread shrimp on skewers. Grill 2 to 3 minutes per side until pink, lightly charred, and curled into a loose C shape.
Warm tortillas on the grill or in a dry skillet for 30 to 45 seconds per side.
Assemble — two to three shrimp per tortilla, a spoonful of pineapple salsa, shredded cabbage, avocado slices, and a drizzle of lime crema. Scatter fresh cilantro and squeeze lime over everything. Serve immediately.