That's really cool, actually. It's what all those luck classes SHOULD have been like (though I'm still partial to the Fatespinner from CArc - just don't take level 5).The most useful are Lucky Start (reroll Initiative), Survivor's Luck (reroll any Save), Magical Fortune (reroll spell damage or caster level check), Make Your Own Luck (reroll any Skill check), and Psychic Luck (reroll psionic power damage or manifester check). But the limited Luck pool means that they're only worth taking if your DM has 1 or 2 encounters per game day.
I have a Luck based homebrew PrC that I wrote up in response to a similar thread months ago somewhere....
Ah, here it is.
The Haply Warrior
3/4 BAB, All Skills as Class Skills, 6 Skill Points per level, d6 hit die, Strong Ref and Will Saves.
Better Lucky then Good (Ex): You gain a pool of Luck points equal to your Haply Warrior class level. As an Immediate Action you may expend one Luck point to re-roll any one roll, such as a Skill check, opposed check, attack roll, damage roll, caster level check, etc. (But as always, you may not make Immediate Actions while you are Flat Footed). If a roll includes multiple dice (such as a damage roll), you may only reroll one die from that dice pool, though you may choose which die to reroll. Your pool of Luck points are replenished after 10 minutes of not making any rolls.
Lucky Miss (Ex): You gain a continuous Miss Chance equal to your 5% times your Fortune's Friend level (max 25% at 5th level). This Miss Chance overlaps with the Miss Chance from any other source (such as a Cloak of Displacement, Blur, etc). In addition, as an Immediate Action you may expend a Luck point to double the Miss Chance provided by Lucky Miss until the start of your next turn.
It's a Trap! (Ex): You add your Haply Warrior class level as a Luck bonus to your AC and Saving Throws during any Surprise Round and against any trap that you encounter. The benefits of this ability stacks with the benefits of Trapsense provided by any other class.
I Like My Odds (Ex): Whenever you initiate the use of an magic or psionic item that requires a random effect, such as a Deck of Many Things or a Bag of Tricks, as an Immediate Action you may expend a Luck point to roll one additional time to determine the effects of the item. You may choose the results of either or both rolls, at your option. In addition, whenever you play a game of chance (cards, dice, roulette, drawing straws, etc) as an Immediate Action you may expend a Luck point to reroll, redraw, or redo any roll, card, or turn, and choose either result. Your DM may expand this ability to include similar situations involving a degree of luck, such as guessing games, answering riddles, etc.
Uncanny Dodge (Ex): You gain the Uncanny Dodge ability. If you already have Uncanny Dodge, you instead gain Improved Uncanny Dodge and your Haply Warrior level stack to determine the minimum Rogue level needed to Flank you.
Damn Your Fool's Luck (Ex): As an Immediate Action you may expend one Luck point to force an opponent to reroll any one roll that targets you. This may include an attack roll, such as a Skill check, opposed check, attack roll, damage roll, caster level check, etc. If a roll includes multiple dice (such as a damage roll) you may only reroll one die from that dice pool, though you may choose which die to reroll.
Fated Destiny (Ex): If you are ever reduced to below -9 hit points or are otherwise killed by any effect (such as a failed Saving Throw that kills you without dealing damage), you may expend all of your remaining Luck Points to instead be reduced to exactly -9 hit points and be Stabilized. You must have at least one Luck Point available in order to use this ability. Using this ability is a Free Action, and may be done during anyone's turn, even if you are Flat Footed. Enemies assume that you are dead unless they choose to examine your body and make a successful Sense Motive check (DC = 15 + 1/2 your character level + your Charisma modifier) to determine otherwise. The DM may adjust this Save DC based on the circumstances of your death. For example, if you are not turned to dust by a Disintegrate spell, the opponent who cast the spell is likely to recognize this (though other opponents may not, depending on their knowledge of Spellcraft). Conversely, if you fall down the Spiky Pit of Despair but survive the impact due to this ability, opponents are more far more likely to conclude that you are dead unless they climb down and closely look at your body.