"One can need a Savior without ever committing an actual sin"
That' pretty theoretical since all of us have sinned, but if you have done no sins, why would you need someone to save you from your sins?
"or receiving original sin. One can need a Savior in order to prevent one from receiving original sin."
Original sin is a false teaching. We are not born guilty, we will eventually become guilty by our own choice and actions later on, but only Adam is guilty of what Adam did.
"Therefore, Christ sinned."
Christ is specifically cited as an exception and he would not be able to atone for our sins if he had sins of his own, nobody else is is said to be an exception, nobody else needed to be an exception.
What's really interesting is that according to the Catholic Church, believing that Mary was born without sin is required for salvation. It's right there in the pope's declaration.
Not Mary, according to the Church.
but if you have done no sins, why would you need someone to save you from your sins?
To save you from original sin.
Original sin is a false teaching.
That is the heresy of Pelagianism, condemned in the Third Ecumenical Council at Ephesus in 431.
-A8