fawdda
1 - Add a cooldown to your fire action. Something like :
Var Cooldown = 0;
On fire event (if Cooldown <= 0) Fire bullet; Set Cooldown to 2;
Every tick (if cooldown > 0) substract dt (delta time) from cooldown.
2 - You can create a sprite behind your bullet at every tick. And destroy this sprite after few secs.