WP Plugin Customization: Cartpauj PM

Customize a plug-in for WP: Cartpauj PM 1. Restrict private messaging: Only admin can assign who is allowed to send messages to whom from the registered users 2. Remove the Delete button from the user interface and keep this option within the admin panel 3. Remove the Announcements button from the user interface. 4. Remove the Settings button from the user interface. 5. Add an option "Email the user when he gets new messages" within the admin panel 6. Remove Directory button from the user interface 7. Integrate a scheduling calendar within the editing tools when creating a new message. This tool is going to be used to insert date, day and time while writing a message. Month should be inserted in letters, time in PM AM format. 8. Allowing admin to have access to all users messages 9. Allowing admin to be copied on all messages being sent. The plugin must be compatible with WP Version 3.7.1