B. Physical observations are not to shake one's faith in the Word of God. God says he will part the seas. God says he made the earth in six days. Same thing.
Physical observations can certainly shake you faith in the prophet who says these things, or in the interpreter who who says that is what they mean. God told us in
Deut 18:21 And if you say in your heart, 'How may we know the word that the LORD has not spoken?'-- 22 when a prophet speaks in the name of the LORD, if the word does not come to pass or come true, that is a word that the LORD has not spoken; the prophet has spoken it presumptuously. You need not be afraid of him.
Jer 28:8 The prophets who preceded you and me from ancient times prophesied war, famine, and pestilence against many countries and great kingdoms. Jer 28:9 As for the prophet who prophesies peace, when the word of that prophet comes to pass, then it will be known that the LORD has truly sent the prophet."
If Moses said the sea was going to part and it didn't, should the Israelites have kept following Moses? Not according to the bible.
When bible interpreters tell us God created the world in six literal days, ignoring what Moses himself tells us about God's days in Psalm 90:4, and science shows the interpretation is wrong, should we keep believing the interpreter? No. The interpreter
has spoken presumptuously. You need not be afraid of him. When God speaks, it happens. Physical observations sift the false from the true and rightly shake our faith in false prophecies and wrong interpretations of the Word of God.
God says He will change us "in twinkling of an eye" and have a "day" when "every eye will see." The latter is an afterthought, since the end of things mirrors the beginning of things and hopefully deals with the allegation that statements of what God "will do" are statements to be understood according to a different way of understanding.
An interesting statement given that modern YEC grew out of a movement that predicted the Lord's return around 1844 (the Millerites and the Seventh Day Adventists that emerged from the rubble when that interpretation was shattered by the physical observation that, well, the Lord hadn't actually returned.)
But you are right there are strong resemblances between the first and last things. We have the 'day' of the Lord which may turn out to be a millennium, or longer, who knows? We have both events given by prophecy, because there are no human witnesses to record either. And of course prophecy is full of symbolic language.
Certainly the book of Revelation mirrors the Genesis. We have that snake again, only it isn't actually a snake. We have the tree of life in the paradise of God. We have symbolic people who represent vast multitudes, the bride the harlot. We even have the first and the last wedding in both stories.
But YECs insist on reading one book as figurative and the other as literal history. If we insist on reading read Genesis literally why not Revelation? Should we expect seven headed monsters trampling NewYork and Tokyo?
One thing we can be certain of about Revelation and the end times is that earnest believers have been trying to understand it and getting it wrong again and again from the first century on down. The Millerites were not the first and there have been plenty since. The thing about a lot of prophecies is we only understand them when we actually see the fulfilment. Physical observations reveal what the Word of God meant. We only understood what Messiah was to be, when he came. We will begin to understand the book or Revelation clearly when we see the fulfilment, and we can begin to understand Genesis when we learn from the physical evidence how the world was actually formed.