High Skill Investion Perks:

[Yellena]

Some ideas I had, and not even sure if possible because of NWN mechanics:

With high investment (Skill focus and Epic Skill Focus), each skill gives extra benefits:
◦Animal empathy: Animals and dire animals are never aggresive to you and you may use this skill on more races (like Vermin). Allows you to have an extra dominated creature (allows by this skill only);
◦Appraise: Small chance of getting a random extra gold amount when selling things;
◦Bluff: You have a chance of selling stolen goods as normal items (rolled once per reset). More NPC options. Chance of making encounters with inteligent creatures you can communicate with neutral ("I am a powerful mage, let me pass or I shall turn you all into dust!");
◦Concentration: Faster learning (possible only applied to languages) and resting (you are more effective when studing spells or meditating);
◦Disable Trap: Faster trap working;
◦Discipline: Has a small chance to avoid being knocked down. Does not stack with dtumble skill's version;
◦Heal: Can use healing without Kits, but possible with skill penalty;
◦Hide: Slight increse in the move speed when under stealth mode;
◦Intimidate: Small chance of making creatures neutral to you (so spawed monster may not be aways hostile);
◦Listen: Slight increase in detection range against MS and in talk/whisper range;
◦Lore: Learns languages faster, if it's higher than spot, it's base value (no skill buffs, like appraise on merchants) can be used against disguises. Chance of knowing/showing enemies properties (like regeneration, DR, SR and so on).
◦Move Silently: Slight increse in the move speed when under stealth mode;
◦Open Lock: Faster lockpicking and ability to copy keys.
◦Parry: Allows the block of one extra attack a round or reduces the requeriment to make a riposte attack, or gives attack/dmg bonuses with Parry Mode on;
◦Perform: Slight increase in song/curse song radius. Small random cummulative income of gold (and maybe XP according to the audience and performance, but the XP is limited to once per day) when performing in public. Stack with Artist and Epic Reputation;
◦Persuade: Small chance of making inteligent creatures or creature you can communicate with neutral to you (so spawed monster may not be aways hostile) and more NPC options;
◦Pick pocket: Not sure how the NPC items are set, but this could give a chance to steal a non-plot item but that isn't marked as "pickpocketable";
◦Search: Slight increases detection radius;
◦Set trap: Faster trap working and either increases trap damage/effect or increase their save's DC;
◦Spellcraft: Reduces costs when crafting magical items;
◦Spot: Slight increase in detection range against hide. Chance of showing enemies properties after engaged;
◦Taunt: Reduces the cooldown needed to "re-use";
◦Tumble: Has a small chance to avoid being knocked down. Does not stack with discipline skill's version;
◦Use Magic Device: You don't blow things up if you fail.

Another skills that are not often considered for being considered underpowered, but that could have extra effects because of the RP they allows/"sacrifice" made:

◦Alertness: When you are sleeping in a dangerous area and monsters would spawn and get you with pants in hand, you have a chance of waking up before they spawn (notices the approach);
◦Artist: Small random income of gold (and maybe XP according to the audience and performance, but the XP is limited to once per day) when performing in public. Stack with Skill Focus and Epic Reputation;
◦Bullheaded: Very small chance of negating a mind effect on you (1~5%?);
◦Courteous magocracy: Slight cost reduction when dealing with scrolls and mage stuff;
◦Silver palm: Every time you loot gold, you get aways a bit more;
◦Snake blood: Very small chance of poisoning those who attack you with melee weapons (saves still applies);
◦Stealthy: Very small increase in movement speed when under stealth mode;
◦Strong soul: Very small chance of negating a death effect on you (1~5%?);
◦Thug: Small chance of negating aggresiveness of "bandit" types, based in your level. At higher levels maybe they even help you hoping for some money. Bandit leaders will aways be agressive (they dislike competition).

◦Epic Reputation: Increases the income when performing, enemies of the same race or similar have a chance of not be aggresive with you (stacks with similar effects). Opens more NPC options and effects that could be based in the players skills, class and faction. Such effects could vary from free services, chance of getting a follower NPC (like a rogue master spawns a group of "badits". Depending on the Intimidate/Persuade/Bluff skill, they could help the PC in the travel for pure fear, admiration or some gold (a dialog could open giving options when a "neutral spawn" ~that happened because of the skill suggestions above~ occurs). Regarding factions, this could have some drawbacks too, like a disguise penalty against the oposed faction, if not disguised, enemy factions are aware of you when you are some areas away (you reach a tavern in the city and as you are famous, people comment about you, and the enemy passing in the street will know you are in the tavern ~people talk, and new gossips fly faster than birds~)
◦Perfect Health: considering this feat is a bit obsolete at higher levels (where you can get it), it could give +1 Regeneration, increase alchohol tolerance and reduces resting decrease rate and resting time.