Is the hadith about the virtue of reciting Surat Al-Fatihah in one breath authentic, which is mentioned in Tafsir Al-Sawi, narrated from the Messenger of Allah, may Allah bless him and grant him peace, and Gabriel, and from Allah?

Reciting Al-Fatiha in a single breath is permissible, as long as it does not lead to a defect in the pronunciation or attribute of a letter, or alter the meaning. There is no hadith that encourages this practice. Rather, the preferable method is to pause at the end of each verse, as the Prophet, peace and blessings be upon him, did, in accordance with the Almighty's saying: "And recite the Qur'an with [proper] recitation."