How did Gabriel study the Qur’an with the Messenger of Allah (peace and blessings be upon him) in Ramadan? Does this indicate the superiority of gathering to recite the Qur’an over individual recitation? And is the night better for reciting the Qur’an than the day?

The method of studying the Qur'an is summarized by referring to the Muslim's own state. If meeting with his brethren makes his heart more submissive and benefits him more in knowledge, then that is better. Otherwise, solitude is preferable. Gabriel's study with the Prophet, peace and blessings be upon him, was to firmly establish the Qur'an in his heart. It is preferable for a person to study the Qur'an at any time that suits him and benefits him, as the Messenger of Allah, peace and blessings be upon him, said: "Be keen on what benefits you."