Many, many thanks for this detailed solution and your snippets!
Meanwhile i tried it with a "if user.isAdmin" condition in the my-sites.get.html.ftl, but your approach seems to be much better and more flexible and also comprises the dashlets link.
But i noticed that there is no "user-welcome.get.js" in my original alfresco folder "dashlets"….
EDIT: i should have looked more precisely in your "user-welcome.get.js", its only your additional code in there, so please ignore the sentence above…
the problem can be marked as solved.
thanks again,
Volker