Hmmm. They appear to be the same length as a jo, but they are more like wooden spears. Osensei was fond of short spears.
Correct, but from my experience, the Tiaha is not thrown as you would a spear, this is not to say you can't, but the club end may impede flight. The circular movements and thrusts of the Tiaha are close to some Jo movements. Example of the "Hasso" Technique, you can see in the video where us Maori perform a similar Technique and stance.