99% of The Muslims (Ahlul Sunnah) believe in al Mahdi. So if the purpose of this thread is to prove to us that he exists then that's useless and so are some of the Narrations you posted, These are all The SAHIH Mutawatir Narrations regarding the Mahdi from the books of Ahlul SUnnah:
What we learn from the Authentic narrations is:
-There will be great disputes and conflicts and earthquakes ect...
-He will appear at the end of times.
-He is from the progeny of the Prophet PBUH from the children of Fatima (RA).
-Everyone in the heavens and on earth will be pleased with his rule.
-Allah will enforce his appearance within a night (i.e., his coming is very unpredictable and is very sudden).
-His name will be the Prophet's PBUH name and his father's name will match the name of the Prophet's PBUH father (Muhammad Ibn Abdullah).
-There will be bountiful favours and he will be generous and distribute money and the fruits will grow ect...
-He will tell Jesus PBUH to stand as the Imam of prayer but Jesus PBUH will insist on standing behind them.
-Even if one day from amongst the days of the Lord remains, Allah will send this Mahdi, meaning he will surely come at the end of times.
-He is a Man amongst the Arabs.
-He will rule seven or eight or nine years.
Nothing about being from the progeny of Hussein RA from his persian wife, Nothing about him being a twelfth Imam, he is referred to as Caliph and Ameer, His name shall be Muhammad Ibn Abdullah not Ibn al Hassan al Askari...
Nothing to do with Shiism and their Mahdi.