In a small bowl, combine the paprika, chili powder, cumin, and cayenne. Rub spice moisture into the fish and let sit for 20 minutes.
While cod is seasoning make the slaw: In a large bowl, whisk together mayonnaise, lime juice, cilantro/parsley and honey. Stir in cabbage, corn, and jalapeño. Season with salt and pepper.
Put a large nonstick pan on medium-high heat, then drizzle the cod with olive oil and season the fish with salt and pepper. Add fish flesh side-down. Cook until opaque and cooked through, three to five minutes per side. Let rest five minutes before flaking with a fork, then squeeze lime into it.
Assemble tacos: Serve fish over grilled tortillas with corn slaw and avocado. Squeeze more lime juice on top and garnish with sour cream.