The original images will not be touched, instead a tag file is created with a link to the rotated image. Using this link rotozoom knows how you would like have your images rotated.
When you open an image folder with 30 images for the 1st time, it takes no more than 30 key pressed or mouse clicks to sort them once and for all. Images that are to be removed can be selected for 'deletion'. At the end of your session when you close rotozoom, the application will ask you to whether or not to move the selected images to the deletion folder. This way deleted images will never be deleted by accident.
Rotozoom is an image viewer like you have never seen before. It can be controlled by the mouse, by a keyboard or by a touchscreen. Most users will use a combination though.