Late reply to be sure but better late than never.
The Edited folder cannot be removed. If you added captions or modified your photos in any way, they are automatically copied to the Edited folder. The only way to remove them from the edited folder is to revert the photos back to their original state and remove the captions. The photo will go to the "Photo Box" folder where it can be deleted. This is how it works on the iPad.
There is a supposed "bug" on the iPhone version of iPhoto where the photo will remain in the Edited folder after you have deleted the captions and reverted the photo.
You can "hide" the photos but it doesn't delete them if you have added a caption (even if you delete the caption). I believe this is a current "bug" in the iPhone version.
I suggest sending feedback to Apple about it if you are experiencing it also.