If I have no Wifi card in the computer and no ethernet cable plugged in then I've removed the internet attack vector entirely.
You would eventually have to air gap the computer again to generate more keys or make a transaction
What is being described here it not an airgapped device. An airgapped device doesn't not have access to the internet, and will never have access to the internet again. Unplugging the ethernet cable doesn't allow you to airgap the device "again", it simply disconnects the device. If you are ever going to plug that ethernet cable back in, then it's not an airgapped device.
Disconnecting a computer in this way, even if booting from a live USB/CD, does not guarantee safety by any means.