Is it obligatory to repeat the prayers that were performed with an incomplete ghusl due to ignorance of the obligation to wash the ears, or the water not reaching certain parts of the body? And is it permissible to adopt the view of Ibn Taymiyyah regarding the non-obligation of making up for missed fasts for one who neglected them without a valid excuse?

Shaykh al-Islam Ibn Taymiyyah is of the view that whoever omits a condition of prayer out of ignorance is not required to repeat it. Some of the scenarios mentioned fall under this ruling, such as the questioner's ignorance of the necessity of washing the ears. As for what the questioner thought was reached by water but was not, if it was mere doubt, then nothing is incumbent upon him. However, if he became certain of that, then he must make it up. Regarding fasting, Shaykh al-Islam is of the view that whoever intentionally breaks their fast is not prescribed to make it up. The preferred and more cautious approach is to make up whatever prayers and fasts one is certain are obligatory, in order to clear one's conscience and to avoid the difference of opinion with the majority of scholars.