Hi Thorvald,
this is exactly what the drawing templates are made for: Take an existing plan in which you have set the layers the way you want them, clear the contents of the view ports (3-05), set the scale of the view ports back to 1:0 (7-1) and save the drawing as a template (1-6-1).
If you use this template now, the layers are used in the same way as in your original drawing.
There is no way to automatically "hatch" a complete layer. I am not quite sure how this should look like. Could you make an example?
Best regards,
Jens