I'm behind you on the arcpy script learning curve and look on with envy and interest.
Some thoughts...
Have your target locations been set? Maybe the results are output to some other yet to be discovered folder.
I see you have the user input the "outputDIR". Remember: the rasters go into a folder with same name as the dataframe and the vector data goes into a geodatabase with the same name as the file and a dataset with the same name as the dataframe. This is my understanding of the the Arc Hydro default. The geodatabase name may not be that important, but Arc Hydro uses the network feature and that requires the use of the geodatabase. Therefore, having everything simply go to an "outputDIR" may not set up the vector data for the network functions.