I'm afraid not. Apple have limited the iPhone's bluetooth to headset profile only. It doesn't support the HID profile which is needed for a bluetooth keyboard and there's not hardware solution.
As editing word documents, DataViz are said to be releasing Documents2Go in the not too distant future, however without a rewrite by Apple, the OS isn't going to let you open documents from emails except in the viewer. Likewise you won't be able to send a doc as an attachment. There are solutions such as AirSharing that allow you to copy files between your iPhone and computer but since one app doesn't have access to another apps files/directories and there is no common area in memory shared between apps you won't be able to open files copied onto the device in any other app. You wouldn't therefore be able to open a document copied in this manner because Documents2Go would not be able to access it.
In short, the iPhone's cripled OS prevents you from doing anything remotely useful with documents.
