You're right. I probably should have stated exactly what I have tried, but the list is so long and I wanted to get to my problem right away. In anycase, I have tried every single trouble shooting method on that page, along with all the other ones that pop up here in the technical forums regarding error 3007 (although our problem seems to be a little different).
Unfortunately, there still has not been any change in my ability to log on. After hours of trying I managed to log on last night and finally beat normal mode with my wizard. My original intention was to beat normal with every character before I commit to one through inferno, but as it looks like my play time will be severely limited by the authenticating boss, I think I'll just stick with my wizard for the long haul :(.