Facts and fictions about Imam Mahdi - Yasir Qadhi

Do you know that the Holy Ka'ba was invaded in 1979, blood was shed, only because some people claimed that they found the true Mahdi. Even the well known Ulamas of that time were confused by the resemblance of that fake Mahdi (Muhammad ibn Abdullah) with the one Prophet Muhammad (PBUH) described. How would you know that a person is not Mahdi if he demands so? For example, the Ahmedia Movement demands that Mirza Ghulam Ahmed Qadiani was the Mahdi. How would you prove to them that he was a fake person demanding himself as Mahdi. Yasir Qadhi - in this very important lecture tells the Makkah invading story of Juhaiman Ibn Utaiba, and he also tells the signs of true Mahdi, such as
1) His name (by birth) would be Muhammad ibn Abdullah
2) He will flee from Madina to Makka, a group of people will be chasing after him
3) He will have long forhead, sharp nose
4) He will be similar to prophet Muhammad (PBUH) in manners but not in look
5) He will be a descendent of Imam Hasan (R) most probably or Imam Hosain (R)
6) In early part of his life he will not be among the best of the pious men of that time, but one night he will repent and Allah will change his heart and he will become the most pious man
7) He will rule the world for 7 years and only then Dajjal will come
8) People will identify him during Fajr Prayer, in Masjid Al Haram, and people will start taking his bayah (leadership) while he will be standing between Makam-e-Ibrahim and Hajr-e-Aswad.
9) A large group of followers from Khorasan (now Iraq,Iran or Afghanistan) will come to join him.
10) At the time of his arrival Muslims will be in great loss and torture at every corner of the world. But Mahdi will bring great peace throughout the world. Mahdi will rule the world with great justice and happiness for 7 years.
11) His team will fight against Dajjal but will not be able to beat Dajjal
12) Isa Ibn Maryam will return to earth, flying on the shoulders of two angels, in a masjid at Damascus (Syria) at the time of Fajr prayer when Imam Mahdi will about to start Fajr prayer.
13) And this is the last mention of Mahdi in Sahih Hadith. We do not know what will happen to him when Isa Ibn Maryam comes.
and so on ...