Newton was what would now be called a Noahide - a believer in the truth of Judaism and the Hebrew Scriptures, but not a Christian nor a convert to Judaism.
Not from what I've read. I've read that he believed in Christ, but did not have a view of the Trinity that agreed with the Council of Nicea.
Where do you get this from? I've read Newton on the book of Daniel and on the book of Revelation, he was Christian. He specifically says that if the Pharisees were to be blamed for not recognizing the signs of the times related to Christ, how much more will we be to blame after Christ for not recognizing the signs . . . etc. Think you got this nogahide (sounds like a couch) stuff derivatively, not from actually reading Newton. He was a Christian, Bible believing . . . from his treatise on Revelation "And in a word it was the ignorance of the Jews in these Prophecies which caused them to reject the Messiah and by consequences to be not only captivates by the Romans, but to incur eternal damnation."
Newton was a Unitarian, so was Whiston his colleague.