Is it obligatory to utter the Basmala when reciting Surat At-Tawbah from its middle, and why is there no Basmala at its beginning?

It is recommended to maintain the Basmala when starting a recitation from the beginning of a Surah, with the exception of Surat Bara'ah. The reason for the absence of the Basmala at the beginning of Surat At-Tawbah is that the Companions, may Allah be pleased with them, emulated what Uthman ibn Affan, may Allah be pleased with him, did, as it was not written in the Mushaf. This is because the story of Surat At-Tawbah was similar to that of Al-Anfal, and they thought it was part of it. The Messenger of Allah, peace and blessings be upon him, did not clarify whether it was part of it, so they were conjoined without the Basmala.