I haven't read the whole thread, so bear with me if this as come up before.
Islam is an idea and state of being. Islam is the state of being in submission to the one true God. There as always been submission to God because everything and everyone is in submission to God. So there as always been Islam.
Islam didn't start with Noah or Abraham or Moses or Jesus or even Muhammad, it started with God.
In this case if Hinduism or Buddhism promote the idea of surrender. does that mean that Buddhism and Hinduism have existed forever? does it mean that each and every one of us who apply these ideas are Buddhists or Hindus and also Muslim?
This isn't what the OP is asking. as far as I see it we are aiming to discuss the cultural and geographical environment in which Islam evolved. it is common knowledge, that the Pagan and to a certain degree Henotheistic Arabs of the 7th century had regular contact and even lived with Jewish and Christian communities, and even had contact with the Sassanid empire, which was Zoroastrian.
In other words, the Hejaz during the 7th century was an interesting case in which native Arabic traditions and beliefs had a diffusion with Abrahamic faiths, and with Zoroastrianism. The Hunufa shows us how monotheistic ideas of the Abrahamic kind developed in this region, and Muhammad's movement shows us the political quest to change the religious and economic status of the region, starting with Mecca and it's Kaaba, which was a great economic asset for the Quraysh in it's polytheistic era, as all the Arab tribes of the region had to pay various taxes to this Meccan tribe during the months of pilgrimage, further more the Quraysh made sure to make the Kaaba an exclusive site with no alternatives in the region.