I'm really having a little trouble understanding your problem. Thought it might be a problem with the Ninja character, but played around with it a bit and it seems to be fairly reasonable.
Two suggestions:
1. If you have edited a character for a while and seriously changed the original placements of parts, it can be very hard to get back to the initial point. Far better just to delete the character and add another copy from the gallery.
2. It's always a good idea to sketch out the movement you want before trying to program it. For example, you say you want the leg to go up in the air and it disconnects from the hip. Try raising your leg without moving your lower body - something

is going to give in the process. A sketch of your own movements (use a mirror) for an action can be a big help and often recommended by books on classical animation.