Multilingual permission for own nodes problem in book for Author without "ouline permission": confine the author to his own book

The background problem is to translate pages in a book on depth below first level, where the author not has permission to create book outline!
My site has a Book in two language. The top level book is no problem to translate, the problem comes on depth 2 and on lower levels.

When translate a Book page below the first depth the normal way will result in the error message: "This type can't be created outside a book" and the author has no permission to Book Outline

Instead the Author has to make a book-page in the other language on actual depth with the translated text and then link the pages together by the selection of "Select translations for" (Multilingual Content setting)

HERE IS THE PERMISSION PROBLEM:
The selection for the authors role has no alternative to "Add or remove own existing content to translation sets"- WHY?
The permission for Multilingual content is: Administer content translations: Add or remove existing content to translation sets. and it result in a securityproblem where the role gets permission to change the translations links for ALL NODES in the whole SITE ????
As I see it the above permission is open a security risk where the roles can crash all translation in whole site!!

Is there any way to limit the permission rights to own nodes?

The purpose behind my question is to find a way to to confine the author to his own book