Interesting question. Probably no way to know as its not like God can't do it anyway He wants.
Technically, Adam's immortal body never existed as in God's decree Adam's original body was going to end.
Aside:
Premise 1: Before Adam's sin nothing died
Premise 2: Currently, our red blood cells last a month and then die (as best I recall)
Conclusion: Adam never created new blood cells as they were not needed ????? (Who knows? ... lol)
God is Spirit and as such is immaterial. A body has limitations and God does not. Christ's body was mutable and God is not. Therefore, IMO, Christ's body was a creation with a beginning and the dwelling of God the Son justified Christ being God.
Hmmm, probably some debate partly due to definitions lacking.
That is hotly debated. See
https://www.gotquestions.org/could-Jesus-have-sinned.html for discussion
Yes. Only the human nature of Christ could die.