Block access to the admin interface based on user capability. The default is only editors and admins are allowed access, but the required capability c
Yes, you need to edit the plugin file and change the variable on line 21.
Yes. For more information see the codex for [http://codex.wordpress.org/Roles_and_Capabilities#Capabilities Roles and Capabilities]. Once you've chosen a capability, simply edit the plugin file at line 18 and replace "edit_others_posts" with your chosen capability.
If your question is not answered here, you can try contacting me. However, I don't actively support this plugin, so I'm not likely to make changes to meet your requirements, etc. http://www.callum-macdonald.com/contact/