**I found a work-around.   It is probably common knowledge but I just figured out a way.  
** Prepare your default scene as you desire and save any changed sky, mats, and camera settings with a dot set to save those settings to default.br6 in folder that Bryce launches from.

Now save that same scene to the folder where you normally keep and save your Bryce projects.  I named my scene AAA DEFAULT.  This name alphabetically puts the file in front of my other files and is easily identifiable.

From now on instead of selecting "filenew document" to start over,  I select "fileopen" and click the AAA default.  tah dah. 

I'm slow to learn but maybe this will help someone else.