Is repentance accepted from telling someone that he is not one of the seventy thousand who will enter Paradise without reckoning, and is it permissible to say that the Alawi sect is infidel?

Sincere repentance leads to Allah forgiving all sins, even major shirk, as He Almighty says: "Say, 'O My servants who have transgressed against themselves [by sinning], do not despair of the mercy of Allah. Indeed, Allah forgives all sins. Indeed, it is He who is the Forgiving, the Merciful.'" As for the Nusayri or Alawi sect, it is among the sects of atheism and disbelief. They are, by agreement of the Muslims, more disbelieving than the Jews and Christians, and their harm to the Ummah of Muhammad (peace be upon him) is greater than the harm of warring disbelievers. They feign adherence to Shiism and loyalty to the Ahl al-Bayt, but in reality, they do not believe in Allah, nor in His Messenger, nor in His Book, nor in any religion.