When is ignorance an excuse, and is uttering the two Shahadas after an apostatizing act considered repentance and a return to Islam?

One must turn away from and ignore satanic whispers (waswasa), occupy oneself with the remembrance of Allah and the recitation of the Quran, and focus on what benefits one in this life and the hereafter, while supplicating for Allah to remove the affliction. One should not pay attention to Satan's threats of apostasy, for Islam does not disappear except with certainty, and a Muslim does not disbelieve except through an action, saying, or belief that Islamic law has indicated to be major disbelief. The one afflicted with waswasa is not judged to be a disbeliever due to lack of choice. Treatment requires complete avoidance of these thoughts, frequent recitation of the Quran and remembrance of Allah, studying the biographies of the righteous, accompanying scholars, avoiding isolation, seeking psychological treatment, and engaging in supplication and Ruqyah (Islamic incantations). As for the ruling on wearing clothes with a cross on them, it is not permissible, but it does not lead to disbelief merely by doing so. However, it is better to prohibit it, based on what Abu Dawud reported from Aisha, that the Prophet (peace be upon him) did not leave anything with a cross on it but he would cut it off. And Umar ibn al-Khattab used to burn clothes that had a cross on them.