In a recent post in the Apple Aperture discussion group someone asked if Aperture could delete the image files once they have been imported. One thing I should mention is that the images were being imported from a folder not the camera.
In a recent thread in Apple Aperture Discussions Show sizes in inches the OP wanted to have Aperture display the size of the image in inches. The only problem with the request is that an images doesn't have a size until the pixels meet the paper.