Being under a curse represents being cursed. Here it refers to being eternally punished. "Those who rely on ... the law are cursed" or "God will eternally punish those who rely on ... the law" (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-metonymy]])
What is clear can be stated explicitly. AT "The scriptures are clear" or "The scriptures teach clearly" (See: [[rc://en/ta/man/translate/figs-explicit]])
Paul is correcting their believe that if they obeyed the law, God would justify them. AT: "no one is justified before God by obeying the law" or "God does not justify anyone for their obedience to the law" (See: [[rc://en/ta/man/translate/figs-explicit]])
The nominal adjective "righteous" refers to righteous people. AT: "righteous people will live by faith" (See: [[rc://en/ta/man/translate/figs-nominaladj]])