Is the repetition of the complete prayer or the fiery prayer, out of ignorance that it is an innovation, considered polytheism with God, and does that lead to the loss of the reward for these prayers?

That which among your actions conformed to the Shari'ah, you will be rewarded for it. As for that which was reprehensible, it is hoped that Allah will forgive you due to your ignorance. You must strive to seek beneficial knowledge and replace the innovated act with what has been legislated, such as sending blessings upon the Prophet (peace be upon him).