Re the short stick and charging opponent: the short stick held in two hands can also be used for a two-hand horizontal strike, in which the middle of the stick hits the charging opponent. The defender can get his full weight behind the strike. Applied to the face/neck, it could be fatal. I have seen this one used, and it was very effective.
The ready position that's been described doesn't look like much to someone without knowledge of sticks, and a "little" stick may not look very effective to a big guy.
Although Bruce Tegner (1929–1985) is not in vogue, his stick book (Stick Fighting: Self-Defense) was actually pretty darned good.
For one (brief) treatise on short stick, I recommend John Styers' Cold Steel. It can probably be obtained via interlibrary loan, with the help of your local librarian.
It has a single chapter on the stick, but it's very good. He focused on a 22-inch stick and emphasized close quarters. The ready position is left foot forward, with the stick in the right, and with only a few inches protruding from the thumb side of the hand. At ready the r. hand is relaxed and the stick hangs down, not looking "ready" at all. The method used hard, driving punches with the short end of the stick, as well as two-hand smashes with the middle of the stick.
Styers also showed the method for a stick choke from behind. This is a lethal technique for combat use, not a self-defense technique. He also showed some strikes with the stick in a more conventional grip.
The short stick is every bit as effective as others have stated, if the user knows what s/he is doing. Like any other defensive tool, the wielder is more important than the instrument.
Regards,
Dirty Bob