Must one make up prayers that were performed too quickly, by only reciting the Fatiha, omitting the first Tashahhud, and sometimes not remembering the number of rak'ahs?

Prayer holds a great status in Islam; it is the second pillar after the Two Testimonies, the first thing a Muslim will be held accountable for, and its neglect entails severe warnings.

The question included several matters related to prayer: 1. Limiting oneself to Al-Fatihah and omitting a surah: This does not invalidate the prayer according to the majority of scholars, as they consider reciting a surah after Al-Fatihah to be a Sunnah. 2. Omitting the first Tashahhud: It is permissible to follow the Shafi'is, who state that the prayer of one who intentionally omits the first Tashahhud is not invalidated. 3. Devotion (Khushu') in prayer: It is not a condition for its validity. If one is overwhelmed by thoughts to the extent that they do not know how many rak'ahs they have prayed, their prayer is still valid. The agreed-upon hadith indicates that a worshiper's thoughts and the whispers of Satan do not invalidate the prayer as long as they do not omit one of its pillars. 4. Speeding up the recitation of Al-Fatihah: This does not invalidate it unless it leads to a distortion of some letters. 5. Doubting an error in Al-Fatihah: The prayer is valid, as the default is no error until proven with certainty, and an unintentional error in Al-Fatihah does not invalidate the prayer according to the Malikis.

Based on this, past prayers do not need to be made up. However, one should perfect their prayer and not be negligent with it in the future, while increasing supererogatory prayers to compensate for any deficiencies in the obligatory ones.