Category and keywords are created at parent publication, there itself we need to assign Write permissions to Author-Groups on Category. Now we don't want the same group to create new keywords in child publications but because of inheritance they can do it.
Now the sad part is even in the Child publication there is no Category Management privilege to this group they can still create new keywords. So if keyword creation is controlled by permissions assigned to group on category then we need to Localize the Category in child publication to make it work, Which we don't want, localization has its own cons to handle.
Any thoughts here for ideal solution in place. (wondering why SDL had not make it as Category and Keyword Management Privilege to keep it simple and easy :( )