Place flour in a small skillet; cook 5 minutes over medium heat or until flour is brown, stirring constantly. Place in a small bowl; cool.
Cook bacon in a Dutch oven over medium-high heat 3 minutes. Add onion, bell pepper, celery, and garlic; sauté 10 minutes or until vegetables are tender and lightly browned. Add water, and cook 1 minute, stirring constantly.
Combine toasted flour and 1 can of chicken broth in a medium bowl, stirring well with a whisk. Gradually pour broth mixture into pan. Stir in remaining can of chicken broth, Cajun seasoning, 1/2 teaspoon salt, crushed red pepper, and cut okra; bring to a boil. Cover, reduce heat, and simmer 15 minutes.
Add shrimp; cook 3 minutes or until shrimp are done. Gently stir in crabmeat. Remove from heat; serve gumbo over rice. Serve with hot pepper sauce, if desired.