What is the ruling on disagreeing with the Imam in recitation and movements, such as saying "Maaliki Yawm Ad-Deen" while the Imam says "Maliki," or the worshiper clasping their hands while the Imam does not? And what is the effect of that on the prayer?

There is nothing wrong with differing from the Imam in recitation, because both recitations are correct, belonging to the seven widely transmitted (mutawatir) recitations. Nor does it harm for the worshipper to differ from the Imam in grasping (qabd) or letting down (sadl) the hands, because grasping is a confirmed Sunnah from the Messenger of Allah, peace and blessings be upon him, but it is not obligatory.