You avoided dealing with Jesus obtaining eternal redemption?
There's no reason to "deal with" anything of the sort. Jesus, our Lord and our God (as Thomas said in John 20:28), is our Redeemer, and as such was never in need of redemption unto or reconciliation with the Father. He always possessed the same glory as the Father from all eternity (John 17:5). Jesus, because He is God, became also man and accomplished the redemption of those He came to save ~ reconciled us to the Father ~ by keeping the Law perfectly and through His death on the cross (Philippians 2:5-11).
Was God able to save His son from Death?
Well sure, but He didn't. If He had, none of us would have any hope of redemption/salvation. As Paul says, if Christ has not been raised, our faith is futile and we are still in our sins (1 Corinthians 15:17). As you said, Christ had the same nature as we do - precisely the same no difference at all, which is true in that he was 100% of man ~ human ~
but He was (and is) also 100% of God. He only ~ "only," as if it is some mere thing; it is not ~ laid aside His Godly nature to accomplish our redemption (again, Philippians 2:5-11).
What we actually could say, F2F, is that Jesus
redeemed Himself by fulfilling the Law perfectly and remaining without sin. So there's how to "deal with" Jesus "obtaining eternal redemption." :)
As for the everlasting covenant, F2F, Jesus Himself
is the everlasting Covenant, the Fulfillment of it, the One that all of the lesser covenants (with Adam and Eve, with Noah, with Abraham, with David) pointed to.
I've opened many doors but so few enter.
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chuckles...> Well, F2F, Jesus is the door, as He Himself said, and anyone who enters by Him will be saved (John 10:7, John 10:9). He's the only door I need. :)
Grace and peace to you.