I'm about to add these to the Frank & K pdf, and here's a few potential issues I caught while reading them:
Alertness:
I would switch the 14/19 rank abilities. Blindsense is ungodly awesome, and the 19 rank ability isn't really that great at all when you have blindsense.
Animal Affinity:
How often can you use the 14 rank ability? Once per day? At will?
Battlefield Surgeon:
The 19 rank ability seems really excessively expensive. I understand that you want it a bit more expensive than True Resurrection, but True Resurrection is half the cost of that, doesn't have a 24 hour limit, and can affect those things that this ability cannot.
Con Artist:
The rank 4 ability -- don't you mean bonus on Bluff checks, not Diplomacy checks? And maybe it should be ranks in the skill, because you can push up your bonus on checks disgustingly high.
Cryptographer:
This seems rather weak. I know that Decipher Script is a weak skill anyway, but that should mean that the feat transforms it into something you'd actually want to spend ranks in.
Deft Fingers:
The rank 4 ability means that someone will hide as many daggers as they want somewhere on their person, draw one, throw/attack, drop (free action), draw another, throw/attack, drop, etc., and have their opponent denied their dexterity bonus on all of the attacks. I don't think that this is intentional.
Dreadful Demeanor:
For the 19 rank ability, how long are they cowered for?
Ghost Step:
From first blush, the rank 19 ability looks...rather powerful. I'm not saying it is, because I really don't know if that's level appropriate when you hit level 16 or not. I'm just saying an explanation of why that's cool at level 16 or a second opinion would be really cool.
Investigator:
I'm not really sure how often it comes up in game, so I'd say that this is kind of wimpy until you get the rank 19 ability (at which point it's pretty cool).
Item Master:
* The rank 14 ability should be changed to work with the 8-magic-item limit, instead of slotted magic items.
* When you use the rank 19 ability, does anything special happen for spells that have costly material components? (By Book of Gears, we have no XP components anymore so that's not an issue.)
Leap of the Heavens:
We already discussed this one.
Legendary Wrangler:
I have nothing bad to say about this one. I just want to mention it specifically because it's
so damn cool.
Magical Aptitude:
Seems good, but is there a different option for this feat without the counterspell abilities? I ask because I have my own counterspell [metamagic] feat forthcoming
Many Faced:
The rank 14 ability seems majorly weak for something you get at level 11, especially because a Hat of Disguise does this as a standard action anyway. Might I suggest emulating
polymorph self for the rank 14 ability?
Persuasive:
Is this necessary? Diplomacy is a hideously powerful skill as it is; I seriously don't think a feat to make it even better is a good idea.
Professional Luddite:
According to the Book of Gears, you can already disable existing magical effects with Disable Device. You talked about this under the Disable Device entry, though. So it should be alright.
Steady Dance:
* Rank 9: What does it mean if your opponent is balancing?
* Rank 14: Balance DCs don't get too high to begin with, so this doesn't seem useful.
Super Scaler:
Climb is useless when everyone starts flying. Same problem as Jump. This feat needs to somehow make Climb continue to be useful.
Swim like a Fish:
The rank 19 ability means that you're never going to get hit if you're in an underwater campaign and you reach level 16. That seems really excessive.