Excellent summary MilvianForce.
You forgot three things about early Islamic history; the Treaty of Hudaybiya, the Ridda Wars, and the Satanic Verses.
The Treaty of Hudaybiya was a ceasefire signed by Muhammad/Muslims and Pagan Quraysh tribe where they agreed to a 10 year truce of no war. Muhammad was forced to sign this because the Pagans were still too strong. About 2-3 years into the treaty, the Pagans became very weakened. When Muhammad saw that their guard was down and that they were weaker, he immediately broke the treaty and conquered all of Mecca from the Pagans. Funny enough he spared almost all of the Pagans in Mecca because they were from his tribe. Notice the irony? He genocided many (like the Banu Qurayza Jews) but spares his tribal own kinfolk from genocide.
As soon as Muhammad died a large portion of Muslims went back to their Pagan faith. Abu Bakr, the new caliph, carried out a civil war to kill or reconvert-by-force those Muslims who became Pagans. This was called the Ridda Wars. A bloody affair that saw the Muslims victorious. That's because Islam allows the killing of apostates (Muslims who leave their religion). They have to use force to keep people from leaving their religion, even back then in Muhammad's time. There is no free will or voluntary choice in Islam, only submission through fear/force.
The angel Gabriel that Muhammad saw was most likely the devil (even the devil can appear as an angel of light). This is further confirmed when Muhammad was given a revelation from the devil but couldn't differentiate it from "Gabriel"; this controversy is known in Islam as "The Satanic Verses". Muslims explain that away as a simple one-off event.
This man is nothing other than a false prophet with a false religion. Sadly this is misguiding billions away from Christ.
Again we see Jesus Christ warning us of such evil.
"Beware of false prophets, which come to you in sheep's clothing, but inwardly they are ravening wolves. Ye shall know them by their fruits. Do men gather grapes of thorns, or figs of thistles? Even so every good tree bringeth forth good fruit; but a corrupt tree bringeth forth evil fruit." Matthew 7:15-17
Thanks, I appreciate the compliment. You bring up three very good points: The treaty of Hudaybiya, The Ridda wars (which I was just about to type and The Satanic verses). You explained them well, kudos for actually knowing these three things, especially the treaty and the Ridda wars. Let's also throw in the fact that Muhammad made his adoptive son Zayd, divorce his wife (Zaynab) so that he could have her for himself. We call that lust, a vice that should be controlled and has stated: "Thou shoult not covet another mans wife" apparently Muhammad didn't get the memo.