Ebony does two of those, and one of the cats does the other. We've always laughed at Eb sitting like a human, she sits all the way back on her butt and puts her legs out in front, sometimes leaning sideways on the couch in the classic "frat-boy lounge" pose. When she has to potty, she'll piddle anywhere she feels like it, but there's a particular stretch of lawn near the pasture fence that's her special #2 spot. Anywhere along that strip is fair game for poops, and she'll spend 10 minutes snuffling around to find the perfect spot, scratch up a patch of dirt (in winter, she digs a hole!), and do her business. She doesn't chew her nails, but our dilute calico cat will, to the accompaniment of loud cracks and licky noises.
Eb's pretty normal in other respects, I think. Or possible I just assumeshe's normal! She not-so-subtly roots her head up under our hands when we're not quick enough on petting her. Sometimes she misses and jacks your elbow and nails you in the ribs, all of which is generally followed by the "sad-eye-stare" mastiff do so well so you can't possibly be upset with her. She sometimes washes her feet, but I've seen a lot of dogs do that. She tries to play with the cats sometimes, but hasn't yet gotten them to join her. She leaps into the room, crashes down into a play-bow and wiggles her butt. The cats generally give her the thousand-yard-stare or hiss and walk away. Guess that's not really odd so much as worrisome LOL, have to make sure she doesn't actually try wrestling with them!
~Marrow