"By the same token, Blessed Mary was born mortal -- yet the Church in the West holds that she never died."
That is not true. We hold that she died, but that she did not suffer the corruption of the grave.
"The consequence of the original sin is dying, not sinning."
It is more than just dying the natural death, it is the loss of grace as well which leads to the second death.
"If anything, I would say that it is more likely Mary chose not to sin."
We would agree with this but say that it was due to grace that she was able to choose not to sin.
Yes, because she was cleansed of all sin (for the second time -- first being at Annunciation), at her death.
We would agree with this but say that it was due to grace that she was able to choose not to sin
Isn't that true for all who receive Grace?