Spiritual death of the soul is not the same as physical death wotsup.
When in Ezekial it says the soul shall die, it is clearly not related in any way to the physical body (as you assert) because we are all sinners and our bodies are alive today. The condition of the soul is always immortal, but the "death of the soul" is not to be seen as the end of its existence.
God saying "all souls are mine" implies it again is a spiritual reality, because the body must return to dust. God is not dust. God is a spirit, and so the soul returns to spirit as Ezekial states.
It's very clear and obvious. God is not dust, but the body returns to dust as the Bible states.