Hello,
yeah, the German forum is very quiet - I was trying to be active for a while (way back in 2012/2013), but after a while without any questions / discussions, I simply forgot to go back there.
Unfortunately, "Create from template" only copies the structures and does nothing with permissions, so the default behaviour triggeres (no local rights and inheritance from parent).
You will have to work with some JavaScript scripting to get this to work the way you want. One option would be to set up a rule on the Sites folder that applies to all sub-folders and triggers on the creation of a new folder. You can put a script into the Data Dictionary/Scripts folder that can be triggered from the rule. This script would then have to check the folder to see if it has been created from a template (that information is not transported otherwise) and then apply the custom permissions.
All of this - so far - can be done without Java programming or server restarts. The only "programming" required is related to JavaScript and usage of the Alfresco Script API.
Regards
Axel