wideawake, you wrote:
“And there really isn’t any evidence that the church doors of Wittenberg were used as bulletin boards.”
I’m not sure about that. On the one hand, Iserloh made an absolutely conclusive case that there was no contemporary evidence whatsoever that Luther nailed anything on the church doors of Wittenberg: http://books.google.com/books?id=9HBIAAAAMAAJ&q=erwin+iserloh&dq=erwin+iserloh&hl=en&ei=un6pTrPqN4L40gGek-WQDg&sa=X&oi=book_result&ct=result&resnum=1&ved=0CC0Q6AEwAA
On the other hand, there was Melancthon’s mention in his memoirs decades later of Luther putting something on (”attached”) the “temple” in Wittenberg.
Anyway, Protestants responded to Iserloh quickly enough (though ineffectively) through Kurt Aland’s book: Martin Luther’s 95 Theses.
Newer evidence was found just a few years ago which adds more credence to Luther’s story, but there is still no conclusive evidence. Look into the discovery made by Martin Treu in 2006 in Georg Rörer’s New Testament in 1540.
What ultimately is most important is not on the nailing up of the theses, but the bad theology of Luther, his heresy, and his terrible character flaws.
I addressed the supposed Roerer “evidence” upthread. And Melanchthon was not present - he was telling a story he heard from someone else. The story is a legend.