Head Start: This is equivalent to +10 Perception for the purpose of starting AP. Way, way, way too powerful. +1 starting AP (equivalent of 2 Perc for casters who don't benefit from the crit chance or other aspects of Perc) would be the appropriate power level. Remember that the default for a talent would be +1 to an attribute, so a limited-utility +2 to an attribute is a fine talent.
Inconspicuous: Interesting. Not really sure how much of a bonus against attacks of opportunity this should provide. One could make the argument for removing the chance completely; one talent gives you the chance to make attacks of opportunity, another talent cancels out the first talent. I'd prefer that, because it would also mean those characters couldn't "soak" attacks of opportunity with a talent called Inconspicuous; AoOs are limited to one per round, so you might want or not want tanking. There's definitely a potential talent in here somewhere.
Warlock: Really don't like this one. Spellcasting abilities are good enough as is.
Iron Fist: Actually hideously overpowered. I don't know how much unarmed fighting you've tried, but unarmed costs 2AP per instance, and each instance delivers 3 blows (might be different holding a shield, haven't tried). With an 80% chance to stun, what that works out to is a 2AP ability with 0 cooldown and a 99.2% chance to stun and a much better chance at getting through Willpower saves. Compare that to perfectly usable skills such as Shocking/Freezing/Petrifying Touch.
Introvert: Another very OP suggestion. An extra point per level is most like 20 ability points. It takes 5 ability points to take a skill from rank 4 to rank 5 (assuming no ability-boosting gear is involved). There are essentially zero instances where a player can line up 4 different abilities to go from rank 4 to rank 5 off of traits, which would be a 20-point equivalent. Remember that the baseline for a talent is to give 2 ability points (All Skilled Up), so in order to justify a talent which gives 20 ability points, you need to take away 18 ability points worth of goodness, and traits, while nice, just aren't worth quite that much. Plus, +1 ability point per level is already a Lone Wolf thing.
(in my defense)
Head Start - a flat bonus of 5 AP per fight really isn't that much. It would let most character use one extra ability, or attack one extra time, once per fight. The value of Perception, imo, has never been the starting AP change (which is negligible in the long run), but rather spotting secrets and increasing range of bows.
Inconspicuous - I felt that the ability to completely negate attacks of opportunity was a bit much. Even so, 40% EXTRA chance of dodging them is pretty good. It's essentially the same as equipping them with a very good shield.
Warlock - The intention was to incentivize hybrid str/magic builds, which I currently feel are underpowered. You're right, though, making magic even more powerful isn't really the answer.
Iron Fist - you're forgetting that unarmed attacks do not have Offense scaling, making you DRASTICALLY less likely to hit with them. That 98% chance to stun is more like a 15% chance, unless the enemy is already cc'd.
Introvert - might be unbalanced, but certainly no more than Glass Canon. Yes, you get 20 extra ability points (slowly, over the course of the game), but you also lose access to tons of immunities (charm, fear, etc), bonuses (crit, backstab) and ability ranks, as a result. It would make the early part of the game rougher, and the later part of the game easier.
