Others have mentioned it, but...
If you can use the Compete Warrior, take a look at the following options:
The Swashbuckler core class. It doesn't make much of a difference to you (unless you swap the 14 Str/14 Int for 12 Str/16 Int), but for most halflings, thier Intelligence bonus is typically higher than thier Strength bonus. Getting enough Swashbuckler levels to use your Int modifier for melee damage, can be a big help.
The Invisible Blade prestige class. It's a rogueish fighter PrC that specializes in fighting with daggers, kukris or punch daggers. They get knife-specific sneak attack damage, and can eventually make feint attempts as a free action.
The Master Thrower prestige class. Great if you want some extra oomph out of thrown weapons. Eventually, you can make touch attacks with thrown weapons.
Strongheart Halflings are the best halfling subrace to pick with thier bonus feat, but they are Forgotten Realms specific; you won't find them in the MM or SRD. Deep halflings are another strong pick, as they get Darkvision, instead of a few skill bonuses.
Also... Don't be afraid to fight dirty and pick up a few multiclass levels of Rogue. Sneak Attack damage really helps small characters deal significant damage.
Finally, I wouldn't bother worrying about Improved Criticals, especially with a small character using a light weapon. The difference between 1d3+2 and 2d3+4 is minimal and occasional. Focus on increasing your bonus damage instead. Get Weapon Specialization ASAP. Doing an extra 2 points of damage on every attack, is much better then doing an extra 4 points (on average) every 4th time (if you're lucky). With that in mind, you might consider using short swords (which deal a little more damage), or daggers (which can be thrown in an emergency) instead of kukris.