Rogue enhancements (history)

Level 1

 * Skill Perception I: +3 Search and Spot
 * Skill Stealth I: +3 Hide and Move Silently
 * Skill Ingenuity I: +3 Open Lock and Disable Device
 * Rogue Action Boost I: Grants the ability to receive short-term boosts to skills (+3 to all skills), weapon damage (+3), or 25% haste (5 uses/rest, lasts 20 seconds, cooldown 30 seconds)
 * Faster Sneak I: 5% increase in speed while sneaking

Level 2

 * Rogue's Dexterity I: +1 Dexterity
 * Price Warfare I: Buffs ally with +x Haggle skill
 * Faster Sneak II: 10% increase in speed while sneaking

Level 3

 * Rogue Action Boost II: Grants the ability to receive short-term boosts to skills (+5 to all skills), weapon damage (+4), or 50% haste (5 uses/rest, lasts 20 seconds, cooldown 30 seconds)
 * Skill Stealth II: +4 Hide and Move Silently
 * Skill Perception II: +4 Search and Spot
 * Skill Ingenuity II: +4 Open Lock and Disable Device
 * Faster Sneak III: 15% increase in speed while sneaking

Level 4

 * Faster Sneak IV: 20% increase in speed while sneaking

Level 5

 * Skill Stealth III: +5 Hide and Move Silently
 * Skill Perception III: +5 Search and Spot
 * Skill Ingenuity III: +5 Open Lock and Disable Device
 * Faster Sneak V: 25% increase in speed while sneaking
 * Rogue's Dexterity II: +2 Dexterity

Level 6

 * Rogue's Action Boost III: Grants the ability to receive short-term boosts to skills (+7 to all skills), weapon damage (+6), or 75% haste (5 uses/rest, lasts 20 seconds, cooldown 30 seconds)
 * Price Warfare II: Buffs ally with +y Haggle skill
 * Improved Trap Sense I: Grants +2 to saves vs. traps
 * Faster Sneak VI: 30% increase in speed while sneaking

Level 7

 * Skill Stealth IV: +6 Hide and Move Silently
 * Skill Perception IV: +6 Search and Spot
 * Skill Ingenuity IV: +6 Open Lock and Disable Device
 * Faster Sneak VII: 35% increase in speed while sneaking

Level 8

 * Faster Sneak VIII: 40% increase in speed while sneaking
 * Rogue's Dexterity III: +3 Dexterity
 * Improved Trap Sense II: Grants an extra +3 bonus on saving throws against traps.

Level 9

 * Skill Stealth V: +7 Hide and Move Silently
 * Skill Perception V: +7 Search and Spot
 * Skill Ingenuity V: +7 Open Lock and Disable Device
 * Faster Sneak IX: 45% increase in speed while sneaking

Level 10

 * Rogue's Action Boost IV: Grants the ability to receive short-term boosts to skills (+10 to all skills), weapon damage (+8), or 100% haste (5 uses/rest, lasts 20 seconds, cooldown 30 seconds)
 * Improved Trap Sense III: Grants an extra +4 bonus on saving throws against traps.
 * Price Warfare III: Buffs ally with +z Haggle skill
 * Faster Sneak X: 50% increase in speed while sneaking

Unconfirmed
The following enhancements appear in the game data files but their implementation has not been confirmed yet:
 * Improved Trap Sense II and III