Is it permissible to remove the niqab due to facing difficulties at work, health problems, marital disputes, its effect on appearance, and the conviction that it is not obligatory?

It is not permissible to work in boys' high schools. A woman should adorn herself for her husband in ways that Allah has permitted, and there is no contradiction between the legal hijab outside the home and adorning oneself for the husband. The husband should not dislike his wife's legal hijab, as it preserves honor and protects the family. Ibn al-Qayyim said: "The root of religion is jealousy (ghirah), and whoever has no jealousy has no religion."