What is the ruling on one who criticizes the reciter in Tarawih prayer for omitting the Basmala between surahs, prostrating in al-Mufassal, and reciting verses from Al-Baqarah after Surat An-Nas, considering this to be a manipulation of madhhabs and a fabrication of narrations?

Criticizing the Imam (prayer leader) who recites the Quran is incorrect. Reciting verses from Surat Al-Baqarah after completing the Quran is permissible and is known as "Al-Hal Al-Murtahil" (the traveler's halt and departure). This has been authentically narrated from the Prophet, peace and blessings be upon him, and was practiced by the Salaf (pious predecessors), as evidenced by various reports. It is also the madhhab (school of thought) of the people of Makkah.

Reciting the Basmala (In the name of Allah, the Most Gracious, the Most Merciful) silently in prayer is the madhhab of Abu Hanifa, Ahmad, and Malik, based on the prophetic guidance. As for abandoning it entirely, that is a less favored view.

Mixing Qira'at (variant readings of the Quran) is permissible if it does not distort the meaning or the grammatical structure, such as omitting the Basmala between two surahs for some reciters, or reading "Kufuwan" with a waw, or the accusative case for "Hammalata" (in Surat Al-Masad). However, it is prohibited if one of the readings is dependent on the other, or if it involves a lie in the narration.

Compiling madhhabs (talfiq al-madhahib) is permissible according to a group of scholars. The Salaf unanimously agreed on the permissibility of seeking fatwas from multiple imams and acting upon their opinions.