In a small bowl stir together tequila, lime juice, olive oil, oregano, sugar, the 2 teaspoons salt, the garlic, and paprika. Set aside 1/2 cup of the tequila mixture to use in the jicama slaw. Pour the remaining tequila mixture over the scallops and shrimp. Seal bag; turn to coat scallops and shrimp. Marinate at room temperature for 15 minutes, turning bag occasionally.