Thanks for a wonderful post, Joe. In regard to relics, we should maybe lighten up just a bit. No one, no pope, no bishop, etc. ever said that they were a necessary part of faith.
As you allude, they are ex voto... just a little something to bring the mind back to the deeds of a saint, or in the case of this shroud, that God became man and needed one for a while.
the Christian faith dates back to times when these mementos were taken a little more seriously ... even in the wrong way. No need for us modern johnnies to go batcrap about it. As much as I sniggered in the duplicate-relic laden churches of Europe, they served their purpose by causing me to reflect (OK fleetingly) upon some aspect of the faith. The Sola Scriptura gang is probably right ... we don't "need" relics. But it is a gift to have them, a gift from Christians who went before us.
The material of the shroud may well date back to Roman times, and be from the Holy Land. Either way, it's a wonderful and gentle reminder of the truth of the Resurrection.
From a modern perspective the veneration of icons, relics, etc., may seem a bit silly, but when placed in the context of widespread illiteracy, the visual vocabulary of Christian iconography can be recognized for the prominent role it played in illustrating, transmitting and communicating Christian beliefs.
Because of the reliance on iconography as a visual vocabulary to communicate specific thoughts, stories and traditions, an artist's value was largely gauged in terms of consistency and conformity, not creativity or innovation.
What's unique aout the shroud springing forth in this environment is precisely its lack of precedence.