Image and article security by category

[marks6i]

What is the best way to configure Joomla so that I can define authors and moderators for each category. I have created groups for an author and moderator for each category and in the category I have defined permissions in the category which are appropriate for each of those groups. So far so good.

What I'd like is to allow front-end editing so that authors (and moderators) can upload images (embedded in their articles) which cannot trash/change images for another category. In other words, if I have an images/ directory and I have categories: cat_a, cat_b, cat_c, then the authors and moderators of cat_a can only upload to images/cat_a.
It would also be helpful if they couldn't delete/overwrite the images there (unless granted those rights).

Also, on my front-end editor, there is no place to say what category a new article belongs to. Is this because authors are not given the permission to publish (a task only moderators can do once they have reviewed the article). There should be a dropdown to select a category among categories that the logged-in author has permission to create an article in.

Eventually I can see my site having 20+ moderators and 100+ authors (100+ categories) and I don't want to worry that accidentally files get overwritten or lost. In my example, if a cat_a author uploaded an image to cat_c, where it might never be referenced, down the road, cat_a (and all its references) might be unpublished and then eventually deleted but it would leave the image in cat_a orphaned.

[Webdongle]

What is the best way to configure Joomla so that I can define authors and moderators for each category. I have created groups for an author and moderator for each category and in the category I have defined permissions in the category which are appropriate for each of those groups. So far so good.....

Nope ... so far so bad.

In Global config Allow login for the new groups but nothing else. Then in the Parent Category Permissions set the editing Permissions for the relevant group(s) ... the child Categories will inherit the Permissions. Then in the front end users in the groups (providing the group is selected in the view/access level) will see the Articles but only have Permission to edit (or create in) Categories they have the Permissions for.

e.g.
You have Articles in Football, Cricket and Tennis Categories
The menu items to the Articles and Category blogs are 'Public'

User Groups
Football editor
Football publisher
Cricket editor
Cricket publisher
Tennis editor
Tennis publisher

They all can see Football, Cricket and Tennis Articles but can not edit until you set up the Permissions in the equivalent Parent Category.