Neither of the phrases in the question is correct. The correct wording, in American English, is "for all intents and purposes." In British English, however, the wording of the selfsame idiom is "to...
Unbleached is exactly that - they don't whiten it. This is preferable for people concerned with chemicals in their food and for people who are concerned about the environment. As far as the cooking...
Self rising flour has a leavening agent and salt added to it. You can make it yourself by adding 1 1/4 teaspoons of baking powder and 1/8 teaspoon salt to a cup of all purpose flour.