What is the ruling on ablution and prayers throughout the past years, and does the questioner's ignorance of the correct method invalidate his missed prayers, or does it intercede for him by not requiring their performance?

If you washed your hands at the beginning of wudu with the intention of obligation, your wudu is valid according to those who do not stipulate sequential order. If it was with the intention of recommendation, your wudu is valid according to the Hanafis. There is no need to repeat past prayers.