There's not that many. Part of the joke is giving rather arbitrary numbers to some of these things. I'm sure there ARE lists that have 100 or so down on them, but people only agree on a few.
And Rule 63 is basically 'For any male character you can think of, someone's drawn them as a hot chick'. Expanded, it usually ends up just being gender reversals in fan art.
They're cute in the way real animals are cute. The originals are cute cause they're designed to look like children.
Eh, the 2d ones could be creepy in other ways, considering they're essentially loli's with funny noses. I rewatched the Chipmunk Adventure a little while ago...the Chipette's spend a good chunk of it in harem outfits. Never mind the pantsu service.
Actually, some other news sites have reported it too, so I think their may be some basis to it. I'd still like a confirmed source of the news, though.