Extra Objects
For extra objects in "Create Pro Mission," hold down the right ALT, SHIFT and CTRL keys, then click on the Create Pro Mission. Keep holding the ALT-SHIFT-CTRL and click on the OBJECTS menu and then click on ALL. You'll now have 34 pages instead of 33.
Pro Mission Editor
Hold down right ALT-SHIFT-CONTROL in the main menu and select PRO MISSION EDITOR. Once in the editor, hold right ALT-SHIFT-CONTROL again and go to FILE/LOAD MISSION. This will allow you to select many more missions to edit.