Is not reading the Qur'an for days considered abandoning it? And does reciting remembrances from the Qur'an without holding the Mushaf negate the virtue of its recitation? And is what Sheikh Al-Shinqiti said regarding this correct?

There is no legal (Shari'ah) evidence specifying a certain period after which a person is considered to have abandoned the Qur’an. Reading from the Mushaf (physical copy) is better than reciting from memory, but it is not obligatory. One who recites from memory is not considered to have abandoned it. Describing a person who abandons an act of obedience as deprived does not mean that the act of obedience is obligatory or that its abandonment is sinful.