Dont agree with the OP.
Haste or Sprint Boost would be completely innapropriate for Halflings in my oppinion.
As I understand / percieve it, Halflings get +2 Racial Dexterity because they are exceptionally nimble and practiced in throwing, not because they are particularly fast. Thus a haste or sprint boost doesnt make sense.
I also do not agree at all that Halflings are the worst race in any way at all.
Halfling Sneak Attack and Saves make them the best option for Rogues. They also make really great Bards with one of the best single target buffs in the game (Halfling Companion), and really fairly good Healers, Cleric or FvS. They make good Monks, and good Barbs. They are also decent Fighters and have +1 inherent AC.
Halflings are a really good balanced race.
Should the Halfling Sneak Attack Enhancments cost a little less AP, sure, I can go with that.
Haste / Sprint Boost for Halflings, i dont agree. Haste and Sprint boost should be given to pure Elves, they are the only race that justify it, in my oppinion.