I agree with everything you have posted here....until the last paragraph.I need to correct the first two verses which should be :
Romans 3:25
Hebrews 2:17
These are the four times this word is placed in the NT and of the four there are two variations.
In passages Romans 3:25 and Hebrews 10:17 it is used in the sense of the Mercy Seat in the OT Temple and it means to cover or conceal. But the mercy seat is not the object of this word but what happened to the mercy seat. The blood of the sacrifice for sin was placed on the mercy seat thus cleansing the place for God's presence. Atonement was made and God's judgement or wrath was appeased reconciling man to God. This of course is a picture of Jesus and His work on the cross. the very death of the Goat and the Bull and its blood spread on the Mercy Seat cannot be seen as anything other than appeasement of wrath.
The Passover itself can only be understood as appeasement of God's wrath.
Exo 12:30 And Pharaoh rose up in the night, he and all his servants and all the Egyptians. And there was a great cry in Egypt, for there was not a house where someone was not dead.
Even still looking at OT passages such as:
To the choirmaster: according to Shushan Eduth. A Miktam of David; for instruction; when he strove with Aram-naharaim and with Aram-zobah, and when Joab on his return struck down twelve thousand of Edom in the Valley of Salt. O God, you have rejected us, broken our defenses; you have been angry; oh, restore us.
You have made the land to quake; you have torn it open; repair its breaches, for it totters.
You have made your people see hard things; you have given us wine to drink that made us stagger.
Psalm 60:1-3
Now I will soon pour out my wrath upon you, and spend my anger against you, and judge you according to your ways, and I will punish you for all your abominations.
And my eye will not spare, nor will I have pity. I will punish you according to your ways, while your abominations are in your midst. Then you will know that I am the LORD, who strikes.
Ezekiel 7:8-9
Behold, the name of the LORD comes from afar, burning with his anger, and in thick rising smoke; his lips are full of fury, and his tongue is like a devouring fire; His breath is like an overflowing stream that reaches up to the neck; to sift the nations with the sieve of destruction, and to place on the jaws of the peoples a bridle that leads astray.
You shall have a song as in the night when a holy feast is kept, and gladness of heart, as when one sets out to the sound of the flute to go to the mountain of the LORD, to the Rock of Israel.
And the LORD will cause his majestic voice to be heard and the descending blow of his arm to be seen, in furious anger and a flame of devouring fire, with a cloudburst and storm and hailstones.
Isaiah 30:27-30
The very brutal beating and the way in which Jesus died should be clear evidence of the nature of sin and just how wrathful God is in dealing with it. To argue against the wrath of God being laid on Jesus is to downplay the nature of sin and how God both sees and responds to it. Such an attitude allows sinners to come to the cross standing upright rather than falling prostrate unable to bear the weight of their sin. Further it misrepresents the character of God.
In the passages of 1 John 4:10 and 1 John 2:2
This is a similar but different use of the word but the meaning is still the same. Albert Barnes puts it this way:
"The proper meaning of the word is that of reconciling, appeasing, turning away anger, rendering propitious or favorable. The idea is, that there is anger or wrath, or that something has been done to offend, and that it is needful to turn away that wrath, or to appease."
Nelsons dictionary defines propitiation as "appeasement".
Further, expiate is not synonymous with propitiation they are, in fact, two very different words. According the Leon Morris in his book "Atonement" he states very clearly that propitiation means "turning away of anger" and expiate means "making amends of a wrong". Replacing one with the other changes not only the tone of the passage but its clear intent and meaning. The followers of Zane Hodges like to do this.
Folks this topic is a Hill on which to die. The downplaying of the satisfaction of God's wrath is an evil of our day and should have no place in orthodox Christianity.
It is disconnected from the rest. You talk about propitiation and turning away anger, but then you go astray with "the satisfying of God's wrath". Where the heck did that come from?