Overview
The Paragon Paths as they stand now appear to not be even close to ready for prime time. There are several serious balance issues with almost all of them. I will talk about some of the general issues and then go into specifics on each one.
Major Issues
Undercosting: For most levels of most Paragon Paths, the daily abilities alone would cost about 5-10 XP were you to buy them separately. Thus, you are only in effect paying 0-5 XP for the passive and active abilities of the level. This is a very low amount to pay, especially given the power of the Paragon Path abilities.
Unlimited on-the-fly resource swapping: Many Paragon Path abilities allow one resource to be used as another resource an unlimited number of times per day. For instance, Champion of the Living L4 allows any per-day fighting skill (e.g. a CA) to be used as a Purify. Often using the “swapped” ability is even more XP-efficient than the class that normally has that ability using it directly. For instance, a CA only costs 3 XP, but it can be used as a Purify which even for a dedicated earth scholar costs 4 XP. And, more importantly, if a scholar memorizes a Purify and ends up not needing it then it is “wasted”, while if a Champion has a CA that he doesn't need to use as a Purify, then he can always use it as a CA. Thus, if Champions were common, there would be almost no need for anyone to actually memorize Purifies – it's a lot more efficient for Champions to use their CA's as Purifies. Normally things that allow you to swap out resources are limited use and/or have a significant cost (e.g. Spell Swap; you have to spend a ritual charge, a Ritual Use point, and 10 seconds of focus) – while here you get to swap the resource out instantly at effectively negative cost. (And as you'll see the Champion's ability isn't even close to being the most powerful one.) There's so many of these I won't call them out one by one below, except for the most egregious ones.
Unfamiliar calls: Some of the Paragon Paths allow for “splicing” effects/qualifiers/deliveries onto other attacks to produce calls which are difficult or impossible to produce any other way. For instance, using the Assassin's L2 power to add Poison and L4 power to change it to Elemental, you can be swinging for “10 Elemental” - that's a very weird call; I don't think there's anything else in the game that swings for Elemental (you can normally throw Elemental, but not swing it.) Even if the rules related to such a swing are clearly defined, more players don't have all the rules memorized and might take a while to figure out what it does, if it's not something they are familiar with from before – you probably don't want this kind of confusion in a fight.
Getting abilities that were removed from the game: As other posters have mentioned, a lot of the Paragon Paths allow for getting abilities such as monster strength and innate reflect magic. As these were abilities that were originally gotten through Master Constructs, and these made Master Constructs so broken they needed to be removed from the game, I am surprised to see them return.
Specific Classes
Auraknife L3-4: Ability to absorb other skills could potentially be broken if you were to, for instance, Charm/Dominate/etc an enemy rogue or mage and force him to transfer lots of spells to you, Also potential for poor player dynamics: the optimal strategy for a group may be to have all the low level rogues/mages operate as “batteries” and transfer their stuff to a high-level Auraknife so the Aurankife can kill all the monsters, but this probably won't be fun for the low level players.
Auraknife L5: So, this basically turns all your Assassinates into Terminates (except that they're guarded against by different things). So it triples the number of Terminates you have available, and also saves you XP to boot. For an Adept wth three Assassinates (the minium to get this) you're getting 21 XP worth of stuff (6 XP dodge, 3 XP 5th level slot, 12 XP for turning two 2-XP Assassinates into 6-XP Terminates) for only 10 XP.
Assassin L1-L4: All this qualifier switching is very likely to confuse players, because it's highly unusual to be swinging for “# Poison” or “# Elemental” (I assume you can use these two together) to change a weapon swing to elemental. Someone not highly familiar with the details of the rules may not know what to do if they get hit with a “50 Elemental Assassinate” from behind, since you almost never see Elemental called on a weapon swing. It's also unclear as to what the advantage of changing a weapon swing to Poison is (since it's blocked by the same stuff as a physical attack, plus some more stuff like poison shield) except that you get to heal 5 off the L1 passive and you could potential change it again to elemental with the L4 passive (is that the point of that? Is the point of the Elemental attack that hitting a shield still counts? Is that how it works? I am not sure I understand the point here.)
Assassin L5: Poison Corrupt? That's a pretty darn powerful spell, that you don't have to have any spell levels to get. I think this is the only way to get a Corrupt that doesn't involve actually having spell slots.
Champion of the Living L4: For the passive: if you activate a batch of 10 CA's, does this trigger 10 times (thus healing you for 50)?
Defender L2: This makes Defenders far better at casting binds than actual scholars are. A scholar needs a 3rd level spell slot to cast a Bind, but a Defender can spellstrike three Binds and then get healed by that same first level spell slot.
Defender L3: This again seems extremely powerful especially since most NPCs don't wear armor so the carrier will probably land as soon as the first hit lands. It seems pretty easy for a Defender to just go down a lime of enemies and drop Weakness on all of them. A small price to pay - the same amount that a scholar would need to buy a mere two Weakness spell slots – for the ability to put Weakness on lots of enemies.
Defender L5: This seems pretty busted. Basically it turns a 5-XP Eviscerate into effectively a 2-XP “Resolute effect” plus probably 100-200 points of healing – which itself would cost around 10-15 XP if a healer was getting that healing from spell slots. So even a single activation of this per adventuring day more than pays for itself, and at this high level you will have at least three Eviscerates. And that's not even counting the monster ability you get.
Disabler L1: Probably this will cause confusion in battle, as using Intoxicate in combat is currently extremely rare, and it isn't actually clear how being Intoxicated affects combat (nothing specific is stated in the rulebook) so this is likely to be very subjective and dependent on the NPC being affected.
Disabler L5: It might be hard to remember which things you can resist and which you can't.
Duelist L1: If I start a CA batch, activate Chosen Foe, and kill my foe, I know I can't “end my foe selection” and get the regular CA effect back (unless I use one of the once-per-day “prematurely ends”) However, can I still start another CA batch that works normally, or am I effectively locked out of using normal CA's for the whole 10 minutes (unless I use one of the per days)?
Elementalist L5: So let me get this straight. If I have a 10-column (about what it would take to qualify for this) and a Potency, then I can empower myself with Ice, use all my 7th and 8th level evocation bolts as Ice (the Potency makes the 7th levels do 40 damage, so it's enough to trigger the ability) and basically throw 20 extra Stun Limbs, all for the low low cost of one 9th level spell slot? And what's even worse, if I want to I can deliberately miss with all the Evocation Bolt packets and only try to hit with the “free” Stun Limb packets, so that I get to Meditate the Evocation Bolt spells back (in only 1 minute for all of them, no less) and do the whole thing again, effectively getting unlimited Stun Limbs without actually expending any spell slots? At the very least you need to specify that you only get to Meditate the Evocation Bolt back if both the Evocation Bolt packet and the “free packet” miss. And also, the trigger works with any source of Elemental damage, so it might end up even more broken if combines with some other source of repeatable Elemental damage (for instance, if you can get your wand damage up to 10, you can throw gobs and gobs of free Disarms)
Healer L1: The ability to effectively turn one spell into multiple spells could easily be broken if combined with other ways to store spells. For instance, one Healer and five Auraknifes in a circle – the Heaer spends one spell and the Auraknifes get a spell back each.
Healer L4: What's the intent of the second sentence of this passive? It seems unlikely that a healer of this high level will be First Aiding friends in combat very often – healing spells are better. It seems like the most common use is to speed up Meditation outside of combat: a healer finds a willing friend (preferably one already at very few HP from the fight), takes him to -1, First Aids him in 40 seconds to meditate a spell back, hits him for 1 again and First Aids him to trigger the meditate again and so on. The RP on this seems really weird, and probably isn't the intent.
Ravager L1-L4: The drawback of the active abilities (having to debuff/harm your friends) seem very easy to circumvent by using it on characters who don't care about those effects (i.e. Weakness on non-weapon-users, Silence on non-casters, Destruction on people way in the back lines or outside of combat, 20 Arcane Body on people who are already bleeding out – and if you're not conscious then you're always willing).
Ravager L5: I'm not sure I like this ability because it turns Berserk into something you want to get. Berserk is actually a hard ability to play correctly because it requires you to attack the nearest target, and the nearest target may be behind you. (The Berserk rules don't specify how often you have to check behind you for potential closer targets.) So it seems like there is a strong incentive here to get deliberately Berserked and “fudge” things by attacking an enemy even if there is a closer ally behind you – and this is very hard to detect.
Ritualist L4: Uh, free reagents? Seems kind of broken. Basically like Conservative Casting, except there's no limits on how many times you can stack it on one ritual.
Skirmisher L1: May want to limit how long you can run for, so that if the Skirmisher is OOG faster than the person he picks up, that the Skirmisher can't just run him far enough away that the carried player doesn't know where he's supposed to go.
Skirmisher L5: A free spellcrafted Spirit Recall!? As a per-day skill that you just need to expend a Riposte for? That seems very easily abusable. I can definitely see this as having a lot of “strategic” use where the Skirmisher use it to teleport between different IG locations. This also seems like the kind of thing that's hard to test in a playtest, because te scenarios where this is broen are the scenarios when you have more people, and more ways to set up multiple circles, etc.
Skirmisher L2: The daytime passive seems way overpowered. If I have let's say 4 backstabs, then effectively this is giving me a 5th and 6th backstab, which would have cost me a total of 57 XP if I were to buy them the normal way.
Skirmisher L3: Half damage to all Normal attacks, effectively? That seems like the kind of thing that normally only monsters get.
Skirmisher L4: A particularly egregious hyperefficient resource swap: you are trading a 1st level spell slot or item (light) for a spell slot or item of up to 6th level.
Skirmisher L5: Whoa! That's a lot of Dodges!
Totemic L4: Whoa! That's a lot of Natural Armor! With a few Improved Assassinates you could get over 100 points of natural armor from this, multiple times a day.
Warden L4: More hyperefficient resource swapping: swap out 10 body points (which only costs a 2nd level spell slot to get back) for one of several spells most of which are 4th-6th level.
Warden L5: This ability seems really powerful – it seems like basically unlimited Spell Parry charges, that don 5 't require a ritual use point to use, plus it can be used on a wider variety of things the only downside is it can only be used on something that hits your friends, not yourself.
Warleader: This class is just the king of ridiculously underpriced resource swapping. Spend a measly 5 body (again, only 1 level of spell required to regain it) to cast any of several different level 4-5 spells? Spend a single Teacher skill (which only costs a measly 1 XP, no less) to hand out four or five Elemental Blades or Healing Blades, or recharge any skill in the game? Use a single Parry to make your friend immune from all non-massive weapon strikes for five seconds as long as you stand next to him?
Warsmith L2: A similar issue to Healer L4 – you just find some random guy and keep refitting his armor (you're probably a master blacksmith so it takes 30 seconds) out of combat. At least this time is better, because the RP isn't nearly as weird, and refitting armor is a lot more common in combat than first aid.
