With gap-hub-user-role WordPress plugin you can change user-role (except Administrator) capabilities easy, with a few clicks.
Just turn on check boxes of capabilities you wish to add to the selected role and click "Update" button to save your changes.
That's done.
Add new roles and customize its capabilities according to your needs, from scratch of as a copy of other existing role.
Unnecessary self-made role can be deleted if there are no users whom such role is assigned.
Role assigned every new created user by default may be changed too.
Capabilities could be assigned on per user basis.
You can add new capabilities and remove unnecessary capabilities which could be left from uninstalled plugins.
Multi-site support is provided.
To read more about 'gap-hub-user-role plugin' visit at
http://wordpressplugins.gaphub.com/portfolio/gap-hub-wordpress-user-role.