Did scholars agree on the impermissibility of a person harming himself in any way, such as by wounding, amputating limbs, or exposing oneself to the danger of death? And what are the evidences for that if there is a disagreement?

There is no disagreement among scholars regarding the prohibition of a person harming themselves or exposing themselves to destruction. Allah the Almighty says: (And do not throw yourselves with your own hands into destruction) and (And do not kill yourselves). Furthermore, the Prophet, peace and blessings be upon him, clarified the punishment for whoever kills himself by any means. Jurists have stipulated the obligation for a fasting person to break their fast if they fear destruction, in order to preserve life, based on the saying of the Prophet, peace and blessings be upon him: (There should be no harm nor reciprocating harm).