I have a core joomla hack that allows custom access levels. Could you make iit so that the access levels could be customized or the drop down loads the levels setup on the site?
Currently there is an undocumented feature for a "Trusted Author" user level allowing most publisher rights except for deleting posts, so the author is able to publish to the frontpage. In the mambots\blogg-x_2_0 folder on the server you will find a text file that can be modified and filled with usernames of the users that you wish to give "Trusted Author" status to. The additions need to be in the following format:
user1:User1:user2:User2
Having line breaks in the file will not work. Also in the above example the two usernames for the same apparent user is to get around the case sensitivity problem. Putting usernames into this file will give them permissions in Blogg-X regardless of the userlevel on Joomla!.
This is an undocumented feature because it was originally done for a friend on his site and I had/have intentions of providing a better interface for this in the future. Hopefully this will be of some use to you now.
Can you give me url to the hack that you are currently using or some additional information and I can take a look at it for possible inclusion in the next version.