What is the ruling on saying: "Don't make me curse your religion" or "Don't make me commit apostasy" when angry, and what is the ruling on saying about actors: "Even if they were the ones who died, they would not cease to exist"?

Such statements are forbidden and impermissible. Threatening to commit a sin is not allowed, so how much more so if the threat is to commit disbelief (kufr)? There should be no leniency regarding these statements. In the Hadith: "Indeed, a servant may utter a word that displeases Allah, not attaching any importance to it, and he falls into Hellfire because of it." As for judging some people that they will not repent, that is not permissible, for the knowledge of that is with Allah alone, and it involves presuming to know Allah's will.