I have a question in the book The Islamic Personality, Volume Three, on the subject of “Conflict with What Disrupts Understanding”:When saying that audio evidence does not benefit certainty except after ten conditions..., what is meant by “changing the I’rab الإعراب, the conjugation, and the rational opposition”?

What is the meaning of: "factories of all kinds should be based on war policy"? As stated in the book “The Institutions of State in the Khilafah (Ruling and Administration) "...factories of all kinds must be established on the basis of military policy.” Are there examples of that?

We know that when a Kafir (disbeliever) converts to Islam, all his sins are erased, so what about the good he did while being Kafir? Through explaining the story of the Messenger, on the authority of Hakim bin Hizam, he said: O Messenger of Allah, "Before embracing Islam I used to do good deeds like giving in charity, slave-manumitting, and the keeping of good relations with kith and kin. Shall…

I have two important questions, and I hope that the answer will be as detailed as possible, knowing that the answers that are published are always detailed, but I would like many Shariah evidences