Not all metrics can be exported in 1 DFT, its trial and error, I started with 1 metric then added one in at a time until it wouldnt export then you know which one you need to do in a seperate DFT.
I found that "https://developers.google.com/analytics/devguides/reporting/core/dimsmets?hl=de" looks great for seeing which dimensions will export with the related metrics.
I can't get his task to output any rows though, even though I can "preview" the data within the task - that's the most fustration part.
Did you have to tweak with any config files in c:\program files to get the task to conntact to your google analytics account intially? (I have to tell it to use a proxy server to connect).
I'm stumpted as to why I can't see any output rows, but I can preview them !?!