Mark,
I quite understand, and hope not to have conveyed the impression that one cannot address a single point of doctrine without simultaneously addressing all others!

Rather, I think you would gain clarity by emending passages where you
imply exclusion of active obedience, especially this one with its string of definitions:
the metaphor of payment is relating to a debt we owe to God, and
that debt is otherwise known as obedience or perfection, and
that debt is paid by the Son, to the father, in the Covenant of redemption.
The payment of this debt, which is the perfect and sinless sacrifice of Jesus Christ
into a more balanced form, as in:
the metaphor of payment is relating to a debt we owe to God, and
that debt, which includes both the obligation of perfect obedience and the penalty for all failure to perfectly obey, and
that debt is paid by the Son, to the father, in the Covenant of redemption.
The payment of this debt, which requires both the perfect lifelong obedience and wrath-removing sacrifice of Jesus Christ
at which point you would return to the necessity of propitiation.
Mark, without having read--and without the time or desire to read now--the position of your adversaries, I'm also curious to know in what sense you are using the term "
dualism", which appears in your title and opening line but not thereafter, to describe their theology?