So here is a review of countdown:
-Prevents players from spacing right at the beginning.
-Allows players to examine their opponent because sometimes when multiple people leave, the next person you fight is almost randomized, for example suddenly you are in a fight with hampa, countdown will give you time to notice him and his skill level so you know to shovel him.
-Like said above, gives you time to plan your move, whether to kick, punch, shovel, clap etc so you don't have to rush click your joints.
-Gives some time for players to switch browser before the game begins.
-Whoever leaves/spectates during the countdown will not lose elo rating.
-During countdown, you are not allowed to adjust any joints, but you may move your cursor and camera angle. This also gives the chance for players to get their camera in a good position before the game begins.
-/em may be used during countdown? I'm not sure
-Replays will not include the countdown period.
-It's kinda traditional for every game to have a countdown in the beginning and it's cool ;).
-I propose that the countdown timer is fixed, or maybe the operator may adjust it.
-The Kiai sound will play during the countdown? I'm not sure about this
-Players may purchase different countdown animation from the torishop etc (or even countdown sound)
This is all i can come up with so far.