Does he who says, after one of the prohibitions has been clarified to him, "This is akin to extremism in religion," and then says in anger that "this is something that makes people say something to the effect of 'damn religion'," without attributing the cursing to himself but to people, commit an act of disbelief?

A Muslim must accept the religious ruling and say: "We hear and we obey." Apostasy is the disbelief of a Muslim through an explicit statement, a word that implies it, or an action that involves it, such as throwing the Mus'haf (Qur'an) into filth. Cursing or reviling the religion is a major act of disbelief that expels one from the faith. As for saying, "This is closer to extremism" or "This makes people curse the religion," this is not disbelief. One must be cautious about engaging in takfir (declaring someone an infidel) without establishing proof and removing ambiguity.