Really important to note when it comes to (3) that the elite (and frankly Orientalising) appropriation of ancient Near Eastern artefacts as jewellery has a long colonial history. Cylinder seals are these little cork-shaped cylinders with pictoral or written designs engraved on them, and work the same way as a signet ring in that you could roll them over wet clay to leave an impression of the engraved relief on the clay to dry. They look like this:
(Cylinder seal of First Dynasty of Ur Queen Puabi, found in her tomb, dated circa 2600 BC, with modern impression. Inscription: 𒅤𒀜 𒎏 - Pu3-abi(AD) Nin - Queen Pu-abi. Nicked straight off Wikipedia as it's a fab comparison of seal / relief.)
In the British Museum you can find "Lady Layard's jewellery". Austin Henry Layard is a guy whose academic efforts I'm admittedly very indebted to. He was passionate about Venetian and Roman glass and did a great job re-popularising both styles in the UK, but more importantly he was the assyriologist who excavated Nineveh and the Library of Ashurbanipal—where we've found the majority of the Gilgamesh tablets. Pioneer figure in terms of Near Eastern archaeology... but check this out:
This is a necklace Layard had made for his wife. It uses real cylinder seals.
To quote the British Museum's entry on the item: One cylinder seal is Akkadian (about 2200 BC) and four belong to the second millennium BC, but eight are late Assyrian (about 1000-612 BC). Late Babylonian and Achaemenid stamp seals (about 600-350 BC) are used for the pendants and clasp.
Enid later wrote in her diary that, when they dined with Queen Victoria in 1873, it was 'much admired'.
Ancient Near Eastern artefacts, repurposed as jewellery in a set that doesn't give a single fuck about accurately dating them, let alone treating them with the sort of respect you might perhaps expect of items over four thousand years old. Instead they've become a mark of elite colonial status, an Oriental curiosity utterly separated from their historical context. They're 'old'. They're non-descriptly 'other'. Time and place dissolve into an attractive and vague exoticism.
All while the place these seals have been appropriated from is busy being exploited by the very empire this "jewellery" is being shown off to!
So to bring it back to your third point: you're absolutely right!!! And this has precedence dating right back to the start of Western study (and plundering) of the Ancient Near East. It's a carelessness, it's an ignorance of historical context, and it's explicitly colonial.