All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
First of all, may Allaah increase your zeal to do good. We consider that the questions which you asked are in order to know the truth and not as an objection to the legislation of Allaah because His Legislation is free from contradictions.
Since Allaah has legislated this, then this is enough wisdom. However, it is permissible for a Muslim to seek the wisdom behind that.
We may summarize the answer to your questions in the following points:
1- Undoubtedly, Allaah is All-Knower of everything, but the meaning from this verse and similar verses is to reveal openly the deeds in order to establish evidence on its doer. Allaah judges the people according to what they have actually done and not according to His Knowledge of what they would do in the future.
2- The narration reported by Asmaa’ about them covering of the face and hands is classified by some scholars as Dha’eef [inauthentic] whereas it is classified by others as sound. Even if we presume that it is authentic, it may have been reported before the Hijab was ordained by Allaah. For more benefit, please refer to Fatwa 83033.
3- The People of the Book are the Jews and the Christians and Allaah permitted us eating the meat of animals slaughtered by them because they mention the name of Allaah when they slaughter. Therefore, if it is known that they slaughter it in the name of other than the Name of Allaah, then it becomes impermissible to eat it according to the most predominant opinion of the scholars . Likewise, if it is not slaughtered and was killed by other methods, it is also prohibited.
4- Loving a wife is a natural love upon which Allaah created mankind, and a person is not sinful nor will he be held accountable if this is from a husband to his wife. The same thing applies to loving a non-Muslim father or a non-Muslim child. What is forbidden is to love the falsehood upon which a person is.
Allaah Knows best.