I see some photos have both CC license and Request to license via Getty Images, Could I use those images in my live preview site ?
Many authors have actual approval for using photos in their themes/templates from flickr photographs. So if you don’t have one, use just safe ones from flickr. And use them just in your DEMO. IMHO that’s safe enough.
You could also use photos from Envato’s PhotoDune marketplace – you’ll just need to leave the watermarks in place of course, but they are really good quality IMO.