1. That may be, but they did not write any of the gospels. The Gospel of Matthew is written anonymously and Matthew's name wasn't associated with the text until the 2nd century. Nowhere in the Gospel of Matthew does the author claim to be an eyewitness.
The Gospel of John is also without a named author and was written towards the end of the 1st century when the Jewish Christian group was separating from Judaism as a whole, which is why it's the most hostile of all the gospels towards Jews.
2. I repeat, the Gospel of John is the only one of the gospels which states that Jesus is god and in which Jesus declares himself to be a divine being. That is distinct from mortal beings performing miracles through god's power, as Moses did in Exodus.
3. It was the evolution of the message. They early Jewish Christians were still waiting for the Kingdom of God as they understood it and by the end of the 1st century, the understanding shifted from a worldly kingdom of God to an otherworldly kingdom of God.
4. I can.