Hi
Apologies, I am not sure where you have got to and have missed some of this as it appears in several places….
To set a permission you would need the approprite permission for the node "ChangePermissions", which you do not have from the error.
The Coordinator permission group (role if you must) is normally assigned to a folder. It seems odd that an object level permission would include creating users for the repo as a whole.
You could assign someone as a Coordinator for the whole repo.
This permission can be assigned to people/groups as a global permission in the permissionDefinitions.xml. You may need a new permission group for this including ChangePermissions. This will allow more than adding a user…..
Currently only administrators can manage people.
I suggest you could have (and may be alfresco should have …) a permission associated with the person type like manage people.
This permission could then be assigned to people/groups as a global permission in the permissionDefinitions.xml. The person service could then be protected using this permission, without leaking more general permissions …..
If really you want some people to have full admin rights then you can add them to the admin group in the authority-services-context.xml.
Hope this helps
Regards
Andy