Originally Posted by
TheOOB
This has been discussed before.
While it is true Two-Weapon Fighting and Rapid Shot don't increase your damage output, that are stiff useful feats for three reasons
1) You can attack multiple opponents potentially letting you finish off more than one foe in a round.
2) If you have any non-damaging secondary effects of an attack, you will be able to apply said effect twice(can't think of any right now, but some will exist I am sure)
3) It increases the chance you will cause damage to the foe at the cost of giving you a chance to only do half damage. When rolling two attacks, if one attack misses, the other attack might still hit, thus you are more likely to do some damage on your turn.
The feats are not for everyone, but they do have usefulness.