Hi, try rename your Configuration folder ex. Configuration_OLD, Start Dreamweaver and it will recretate the Configuration folder as a clean one, Close DW, start extention manager remove all extentions.
Cleare the cache.
Don´t install FB2, but install Tool Kit, Don´t install Cookies Toolkit (u have that in AS2), and install other extentions as u like, last u install AS2.
I see u using Mac, not sure where to find the Configfolder on a Mac, maybe you know els do a search for it.
Hope this helps you out a bit.