Does a Muslim woman's failure to adhere to the loose, lawful hijab affect the acceptance of her other deeds and provoke God's wrath, and is this intense fear of a bad end mere whispers (of Shaytan) or divine wrath?

Allah has made the legal hijab obligatory upon women. A garment is not considered legal unless it fulfills the prescribed conditions. Good deeds do not substitute for the hijab. Anyone who imagines that by increasing their prayers and fasting, they are permitted to abandon the hijab, is mistaken, sinful, and ignorant; for the hijab is an obligation from Allah. You must hasten to wear the legal hijab, persist in prayer, lower your gaze, and abandon all other evil deeds. Allah Almighty said: (Indeed, prayer prohibits immorality and wrongdoing, and the remembrance of Allah is greater) [Al-Ankabut:45]. And the remembrance of Allah is a strong fortress against falling into what Allah has forbidden. And among the fruits of a good deed is another good deed.