This wasn't a halfling, but it was the most powerful character I've ever played, so hopefully you can glean something from it.
Forgotten Realms setting. The DM allowed Unearthed Arcana flaws and FR regional feats. 28-pt buy. I played the character from 5th level, and he died just when he would have reached 9th.
Grim Morgensen
Human Ranger 6/Beastmaster 3
Str 14 (13 +1 at 8th level)
Dex 22 (17 + 1 at 4th level +4 enhancement)
Con 14
Int 8
Wis 12
Cha 8
Flaws: Slow (half base speed), Poor Reflexes. My justification was that he had broken his leg once, and hadn't set it right. Which was why he almost never got off his horse.
Feats: Saddleborn (FR regional feat, allows you to take 10 on ride checks, and to make a ride check 1/round in place of a reflex save), Nature Bond (+3 to effective level of animal companion, to a maximum of my actual character level), Point-Blank Shot, Precise Shot, Rapid Shot, Mounted Combat, Multishot, Skill Focus (Handle Animal) (required for beastmaster), Weapon Focus (composite longbow).
I wore +2 mithral breastplate, and managed to afford a +2 bow, gloves of Dex +4, a +1 buckler, and an amulet of natural armor +1. I know, slightly more than typical wealth for that level, but we earned it. My attack bonus was something like +18, and my AC was 25 (or 29 if I took cover behind my mount, which I often did).
My mount was originally a crazygonuts heavy horse that would just wade into combat and trample weak foes. I eventually had to switch to a dire eagle because the rest of the party got giant owl mounts, but I can't say I was sad to be able to stay completely out of the reach of many of my opponents.