Yes.
That God, the infinitely powerful, infinitely wise, and incomprehensible to mortal minds, came among us in a form that we can understand, because he wants us to know him.
That’s a mechanical detail, of no importance.
Yes.
I don’t know. Certainly not before we have made this world a fit place for Him to return to.
What is a miracle? A miracle is a sign from God. It’s anything that makes you aware of God’s presence in the world. It does not have to mean a massive, visible, disruption of the natural order - in fact, since God made the natural order, why would he want, or need, to disturb it? So, yes, the miracles of the Old Testament happened - even if they were reported incorrectly, and even if there’s a scientific explanation for each one, they were still miracles.
If you look at it right, everything is a miracle. So yes, and yes.
In the final analysis, nothing happens that is not God’s will … we have free will, but He knew how we would use it when He made us. Prayer is an attempt to get closer to God, to bring our wills into line with His … if we pray for something, and it happens, we know that it was His will.
Yes, but I don’t know the details.
Anyone who wants to. Anyone who truly wants to be with God will go to Heaven. Anyone who truly wants otherwise will go to Hell - Hell being the state of permanent separation from God.
Anyone who wants to be with God is a Christian, whether they call themselves that or not. (Or whether they know God by that name or not.)
God loves us and wants us to be with Him. So He is in favour of people wanting to be with Him - who are Christians, by my definition above.
If it helps people know God, it’s a good thing. There are people who have no spiritual direction in their life, if anyone can set them on a path to God, this is good. (But God reveals Himself in different ways to all of us, so there is no one right path which everyone must walk.)