Is it safe to delete photos in iPhoto/Aperture, or will this also delete them from my Picturelife library?

Once the photos have been successfully uploaded to Picturelife, it's safe to delete them. Deleting photos from your hard drive/external drive will not affect anything that you've already uploaded to Picturelife. We always recommend checking your Picturelife library before deleting photos, to make sure that you have uploaded those photos.