What is the ruling regarding my prayers and ghusl (whether for menstruation or other reasons) after I discovered that I had been performing ablution incorrectly, as I used to wash my face with water remaining after first washing my hands, and wipe my entire ear instead of just the visible part?

Your question is not entirely clear. However, what is obligatory in washing the face is to pour water over it so that it covers the entire face, and merely wiping is not sufficient. If you completed the washing of the face, then your ablution (wudu') is valid. Otherwise, you must repeat the prayers (salat) that were performed with that ablution. If you are unable to determine their number, then rely on your best estimate. The majority of scholars believe re-performing prayers is obligatory, while Sheikh Al-Islam (Ibn Taymiyyah) holds that it is not obligatory for someone who was ignorant of the ruling. Wiping the ears is a Sunnah (prophetic tradition), and omitting it or wiping them in a non-Sunnah manner does not affect the validity of the ablution. As for the ritual bath (ghusl), what is obligatory is to cover the entire body with water. If you fell short in that, then you must repeat the prayers that were performed with that ghusl.