What is the ruling on praying behind an imam who does not master Al-Fatiha, and what is the ruling on the imamate of someone who commits sins despite mastering recitation?

The one most knowledgeable of God’s Book (the Quran) should lead the prayer (Imamate). If they are equal in that, then the one most knowledgeable of the Sunnah. After that, the one who emigrated earlier, then the one who embraced Islam earlier. And whoever makes a mistake in Al-Fatihah, such that they drop letters or change the meaning, their prayer is invalid, and they must correct it, unless they are unable to do so after striving. As for the Imam who makes mistakes in Al-Fatihah, no one should pray behind him except someone who is at his level or lower in reciting Al-Fatihah correctly. The young man who is proficient in the Quran should be advised to fear God and benefit people. His sister's actions do not harm him, for every soul is pledged for what it has earned. Committing sins does not prevent one from leading prayers or from other acts of goodness. Therefore, he should hasten to do good and avoid evil, renew his intention for God, and marry a righteous woman if possible.