I like the Deadly Precision fix of a flat +1 per 2 sneak ... but I'm math challenged and probably wouldn't complain about the feat as is because reroll 1 is maybe even easier to remember. What does the math come out with for rerolling 1 and 2?
Rerolling 1s & 2s gives you an average of about 4.2, against the standard d6 roll average of 3.5. If +1/2 dice is too hard, my advice is to make it add +1 per die of sneak attack damage or turn the sneak attack dice into d8s. (Both options have the same average - 4.5 - but they give a different range.)
Mobility, at the least, how about change it to say, "You get a +4 dodge bonus to Armor Class against attacks of opportunity when you move into or out of a threatened area. ..." This would cover granting the benefit against moving into a threatened area of a foe with Hold the Line.
It's still very situational, which is the feat's main problem. An option would be to give the character a +2 dodge bonus
if they move. Dictates certain combat options, makes the Lion haiku popular, probably slows down combat.
Open-Minded, How about have it grant the character one or two additional class skills, in addition to gaining the extra skill points. It could be used to potentially open up a prestige classes easier/quicker.
Bad Axe calculated that a feat was worth (at least) 1 skill point per level. Letting
Open-Minded give a character skill points equal to their character level
and one additional skill point each time they gain a new level would not be unbalanced.
It's not problematic in itself. What Trailblazer needs is "Deadlyshot" - a single big ranged attack feat as an answer to "Manyshot". It also needs an equivalent to "Rapid Shot".
Improved Overrun, How about with the feat the character cannot be avoided, is granted a +4 bonus, and can continue making overrun attempts against additional foes until his move is used up, but once a combat maneuver roll fails the character stops.
I haven't tried out the maneuver under Trailblazer and don't feel qualified to comment. (This isn't a mathematical or design philosophy type question and can't be answered
a priori.)
Improved Feint, dunno. A +2 bonus on the skill check to feint, and penalties against nonhumanoids are halved?
Improved Feint is fine. My line about "Underwhelming Attack" was meant to imply a feat that allowed my character to attack in an apparently pitiful manner, leaving her opponents
underwhelmed and vulnerable to more competent violence later. But that's basically what Improved Feint does.
Weapon Focus, I'd hate to make a simple feat more complicated with extra clauses . . . I know the way I'd rule is that if your character had Weapon Focus (piercing), but wields a weapon with piercing/slashing, then the character gets the Weapon Focus bonus on attack rolls with that weapon when used either piercing attacks or slashing attacks.
Ruling is pretty easy. We have a good idea of what the intent is, because we know what Weapon Focus was like in 3.5.
But if Trailblazer is meant to be for people who haven't played 3.5 (i.e. when Bad Axe release a hardcover core rules set), this needs to be ironed out in the feat description.