Well than lets end this discussion here by saying this that i agree with you i have no right to declare someone Muslim or non Muslim all i will say is that if we go by Quran and Prophet Muhammad's teaching than there will be no Prophet after him.
"Muhammad is not the father of any of your men, but (he is) the Apostle of God, and the Seal of the Prophets: and God has full knowledge of all things. (Quran, 33:40)"
Words of Prophet Muhammad (PBUH)
"In My Ummah (Islamic Nation), there shall be born Thirty Grand Liars (Dajjals), each of whom will claim to be a prophet, But I am the Last Prophet; there is No Prophet after Me. (Abu Dawood Vol 2 p. 228; Tirmidhi Vol 2 p.45)"
"Narrated Abu Huraira: The Prophet said, 'The Israelis used to be ruled and guided by prophets: Whenever a prophet died, another would take over his place. There will be no prophet after me, but there will be Caliphs who will increase in number.' The people asked, 'O Allah's Apostle! What do you order us (to do)?' He said, 'Obey the one who will be given the pledge of allegiance first. Fulfil their (i.e. the Caliphs) rights, for Allah will ask them about (any shortcoming) in ruling those Allah has put under their guardianship.' (Translation of Sahih Bukhari, Virtues and Merits of the Prophet (peace be upon him) and his Companions, Volume 4, Book 56, Number 661)"
You were right i need to do more research on this.