I've got a gazillion photos in various files on an old PC and a new Macbook Pro. I'm uploading them all into Lightroom. After that's done can I delete them from the PC and Macbook? My goal is to get every photo in one place, and I'm making that place Lightroom as it works on both platforms and it seems like it will naturally be much easier to go through my photos in Lightroom than anywhere else. I'm also going to upload old DVDs and various memory drive photos to LR as well. Any risks here? Ideally, I'd like all my originals safe forever in the Lightroom cloud, and perhaps later copy them all to an external HD as well. I appreciate any advice.