This is my first attempt on modding. I took the code from viewtopic.php?f=11&t=2805 (many thanks to the author!) and did several changes that focus on realism.
Changes:
Non realistic arrows removed
Every different bow type has different velocity that comes from a formula containing:
1.bow's velocity factor
2.player's hitpoint at the specific time
This works exponentially although a little smoothed. So the less hitpoints the player has the less the velocity of the arrow.
Minimum offset of 1.2 seconds between each shot
Arrows disappear after use even on non creative mode