Is it permissible to read the Quran quickly in Ramadan without understanding some verses and with little recourse to exegesis, and is it necessary to renew ablution to continue reading with frequent flatulence, or is it permissible to read from a computer screen without touching the mushaf?

It is not permissible to rush reading if it compromises the pronunciation of letters and their vowel marks. The most appropriate is to read slowly and with tartīl (recitation). Understanding everything is not a prerequisite to earning reward for reading. However, reading with understanding yields a greater reward.

If one's wuḍūʾ (ablution) is invalidated and it is difficult to renew it, it is better to read from sources other than the Muṣḥaf (physical copy of the Qur’an), such as from memory or a computer.