Paul does not say all fleshy life will be put away at the grave.
Read Paul's words closely that you rely on for your argument.
1 Cor 15:35 But someone will ask, “How are the dead raised?
42 So will it be with the resurrection of the dead.
Paul in several verses explains how the dead are raised.
He contrasts the earthly body with the heavenly body. Does he say all will die? Does he say that the only way to have the heavenly body is to first die. Does he say that on Christ's return all will first die and then be raised in the new spiritual body? No he doesn't. Paul explicitly says those saints alive when Christ returns will be changed without dying. So there is a way to as you say "put away fleshly life" without dying.
You continue to ignore verse 52 as quoted in the OP, but somehow want to use Paul's words in the same chapter. A major point of this OP is that all scripture is true and must be read in whole. This means there may be exceptions to general rules. Scripture in one place may be qualified in another place. We just don't ignore the other scripture because it doesn't agree with one's own understanding.
Now you wish to argue a difference between what it means to EXPERIENCE death vs what it means to die. In all of history do you think only 2 people died "peacefully", without experiencing the "pains" of death? Read scripture to learn this is not the message that scripture is clearly saying.
5 Altogether, Adam lived a total of 930 years, and then he died.
8 Altogether, Seth lived a total of 912 years, and then he died.
11 Altogether, Enosh lived a total of 905 years, and then he died.
14 Altogether, Kenan lived a total of 910 years, and then he died.
17 Altogether, Mahalalel lived a total of 895 years, and then he died.
20 Altogether, Jared lived a total of 962 years, and then he died.
23 Altogether, Enoch lived a total of 365 years. 24 Enoch walked faithfully with God; then he was no more, because God took him away.
27 Altogether, Methuselah lived a total of 969 years, and then he died.
31 Altogether, Lamech lived a total of 777 years, and then he died.
Genesis 5 lists 9 generations. Do you see something unique in the description of their lives? Is there an exception in one of them? Scripture does not deceive. It may hide things though.
Understand that physical death of the body is a curse from God. It was not part of the world at creation.
Understand that God can give earthly life to dust. Not all were born.
Understand that God can create descendants of Abraham out of stones.
Understand that spiritual beings can manifest as physical beings and go back to spiritual beings.
It should be no problem to understand that God can take an earthly body to heaven without dying. Does the earthly body still exits in heaven, I don't think so. Does than mean that the earthly body died? Scripture says it did not. What happened to the earthly body? Not the point of my thread. If something can be given life without being born, than a physical life could be over without death.
I believe that Enoch and Elijah were spared the curse of a physical death just as the saints at Jesus second coming will be "translated" into spiritual beings without dying.