You're shooting in pretty much a pitch black room, what do you expect? "Good in low-light" doesn't mean "good in no light."
On the 2nd video I'm not seeing the lines, might not be high res enough for them to show up. Generally compressed video doesn't handle shadows very well, but I don't see anything out of the ordinary in either shot. I suspect maybe your expectations were a little high for this camera... If you want something that handles the shadows really well try out the Sony FS100.