Place roast in an aluminum foil-lined roasting pan. Sprinkle pork evenly with 1 1/2 tablespoons salt and next 3 ingredients. Sprinkle evenly with 4 tablespoons flour. Pour 2 cups water and vinegar into the bottom of roasting pan. Add onion and garlic cloves. Drizzle pork evenly with hot sauce.
Bake at 375° for 3 1/2 hours or until tender. Remove pork from roasting pan, and wrap in aluminum foil. Pour about 1 cup pan drippings into a 2-cup glass measuring cup. Let stand 10 minutes, and skim fat from drippings.
Melt butter in a large skillet over medium-high heat; whisk in remaining 2 tablespoons flour, pan drippings, broth, wine, and 1/2 teaspoon Italian seasoning. Bring to a boil, whisking constantly; reduce heat to medium, and simmer 10 minutes. Season with salt and pepper to taste. Serve gravy over sliced pork.