Is it permissible to omit an entire part (Juz') of the Qiyam prayer and suffice with only half a part due to the Imam's voice and devotion, knowing that the Imam completes the part in the Tahajjud prayer, and is what matters in the Qiyam prayer the quantity or the quality?

Tarawih prayer is a Sunnah, and there is no specific amount for the recitation within it. It is recommended not to recite less than a full Qur'an (khatmah) during Ramadan due to its virtue. However, if this is difficult for people, it is permissible to lighten the recitation. There is no harm in seeking out mosques and praying behind an Imam with a beautiful voice, as this helps in achieving devotion (khushu') and presence of heart, which leads to great reward. It is better for people to complete what they are accustomed to doing in Ramadan, because the most beloved deeds to Allah are those that are continuous. Muslims should advise each other, cooperate in righteousness and piety, and avoid expressions that are contrary to the etiquette of Islam.