Combine avocado, red bell pepper, and hot sauce in a blender; blend to a semi-chunky consistency. Pour avocado mixture into a saucepan set over medium heat. Stir in tomato sauce, 1 tablespoon at a time, until dipping sauce reaches desired consistency. Cook until thickened and heated through, 5 to 10 minutes. Whisk egg whites, buttermilk, and Italian dressing together in a bowl. Combine crackers, pecans, coconut, paprika, chili powder, coriander, black pepper, dried onion, salt, cumin, and garlic powder in a food processor; pulse into fine crumbs. Pour into a shallow bowl. Dip zucchini slices in the egg mixture; coat each side with cracker mixture. Heat grapeseed oil in a deep skillet over medium-high heat. Cook breaded zucchini slices in batches until golden brown, 1 to 3 minutes per side. Serve with the tomato dipping sauce alongside.