They aren't really.
As an Arab, Mohammed is a descendant of Ishmael, who is Sarah's stepson. However, there are over 2000 years between Ishmael and Mohammed.
Prophet Muhammad was descendant of Prophet Ibrahiem.
yes, refer to related question and related link below.
Hadith is what Prophet Muhammad (pbuh) said while Sunnah is what he (prophet) did.
It was not by prophet Muhammad (PBUH) choice but per God (Allah in Arabic) command to him. It was to honor prophet Muhammad, to confirm support to him, and to strengthen the faith of his followers. refer to related question below.
God (Allah in Arabic) is the Creator. Prophet Muhammad is God prophet per God revelation of Quran to him through the angel Gabriel (Jibril). However, it is to be emphasised that prophet Muhammad is a human who is inspired by God.
The prophet Mohammad is a descendant of Abraham son Ishmael.
Hazrat Uthman was son in law of H Muhammad saw .
Prophet Muhammad is related to Islam, but he was a messenger to all mankind and not only to Muslims.
Allah save prophet Muhammad by spider net.
The religion is Islam. see related question for more information.
Khadija, prophet Muhammad first wife, was the first who recognized Muhammad as a prophet (BPUH).
Islam religion per God Quran revelation to prophet Muhammad is founded by Allah (God in English and same God in Christianity and Judaism) and not prophet Muhammad (peace be upon him). Prophet Muhammad is the God Messenger and prophet who conveyed God message to his followers. Refer to related question below