Trenchcoat brings up a good point.
The best of these feats is basically the Sorcerer ones because they are a "better version" of an existing feat. The Sorceror is basically Mental Toughness on steroids: 105 extra SP with 10 random casts of Elemental Damage spells.
I would love to see more Past Life Feats to work this way.
Barbarian: Gain Toughness Feat. Gain +10 HP
HP is a Barbarian Mainstay. +10 HP is a 1AP level 1 Enhancement.
Bard: Gain Force of Personality Feat. Gain +1 to all Charisma skill checks except for UMD.
Charisma is a Bard's calling card. I figure we can really sell this guy as a slick charismatic fellow. +1 to Diplomacy, Haggle, Perform, Imtimidate, and Bluff checks. This is 5APs worth of level 1 enhancements. And you don't get UMD, which is the one that everyone wants
Cleric: Gain Empower Healing Feat. Gain 5 uses of Cure Moderate Wounds.
Cleric is known for healing. 5 uses of CMW is effectively 16-26 hp healed averaging 21. Empowered, it heals another 10.5 hp for a total of 31.5. With 5 uses it heals averages 157.5 HP. Of course, this can get jacked up with Ardor and other heal enhancement abilities.
Favored Soul: Gain Empower Feat. All empowered spells do 3% more damage (calculated after the Empower).
Blade Barrier averages 48 damage/hit. Empowered it averages 72 damage/hit. With the bonus, it averages 74.16 damage a hit. Of course, you can stack Maximize and all that stuff with it to make the number bigger.
Fighter: Gain Weapon Focus Feat. Gain +1 damage to the chosen weapon type.
Fighters are the masters of their weapons! +1 damage is half of a level 4 feat (which is usually considered worse than the Weapon Focus Feat) and is important only as a stepping stone to Superior Weapon Focus and the Kensai PrC. Which you don't get with this ability.
Monk: Gain Dodge Feat. Gain +3 to Concentration.
Concentration is really something Monks rely on. +3 to concentration is a 6 point AP. But that's okay.
Paladin: Gain Luck of Heroes Feat. Gain +1 to Will Saves.
Paladins are known for their saves. +1 Will save is half of the Iron Will Feat.
Ranger: Gain Two-Weapon Fighting Feat. 3% attack speed boost while dual wielding.
Attack speed really is what Dual Wielding is about. 3% emphasizes that.
Rogue: Gain Weapon Finesse Feat. Gain +1 to saves/AC versus traps.
Rogues are known for being the "anti-trap". +1 versus saves is their Level 3 ability.
Sorcerer: Gain Mental Toughness Feat. Gain 10 uses of random elemental damage spells.
Yes this is the template that I am basing things off of.
Wizard: Gain Heighten Spell Feat. Heightened spells work at an additional +1 DC.
I really wanted to sell the "High DC" aspect of a Wizard versus the "Lots of SP" aspect of the Sorc.
All of these are 'upgraded' versions of existing feats that I think would make the flavor of each class really shine, yet not be overpowered.