What is the ruling on completing the recitation of Al-Fatiha after the imam rises from bowing (ruku'), due to the imam's speed in prayer? And are these actions—mentioned in the question—considered part of the Hanafi school of thought, such as collective dhikr and supplication, reciting Al-Fatiha after the prayer, and delaying the adhan?

Tranquility (طمأنينة) is a pillar of prayer according to the majority of scholars. Its minimum extent is for the worshipper to achieve the slightest stillness. Hanafi jurists have explicitly stated its obligation in bowing (ruku'), prostration (sujud), and the upright posture between them. The imam must be advised gently and kindly so that the congregants can follow him. The congregant must be keen to follow the imam, even if that means limiting oneself to the obligatory acts.

If the imam fails to observe the obligatory tranquility, it is preferable to pray in another mosque. If the congregant is unable to complete Surah Al-Fatihah in the first rak'ah, the remainder of Al-Fatihah is waived for him, or he may continue reciting it.