It seems to be by far the most boring path, which is a shame because it's the one I was the most excited about by a large margin. Lots of its path abilities seem to need a lot of work.
Assured Drinker: Take an extra turn or drink a potion as a swift action. It's an okay ability, but definitely not at the level of the path abilities of the others.
Assured Skill: Not sure of many situations where this would be useful. In combat, you're obviously going to have better options. Outside of combat, most checks aren't that binary anyways.
Astounding Disable: Big step in the right direction. Being able to go from 2d4 rounds to a move action is definitely more mythic.
Critical Skill: Most skill checks don't really take that much time. In most situations, there's absolutely no difference in whether you do something in 10 minutes or 5 minutes, 6 days or 3 days. And most importantly, most of the time you're not going to roll a 20. This is one of the most circumstantial abilities I've ever seen, the point of being almost useless.
Critical Tinkerer: And this one is even more circumstantial.
Defensive Move: It's nice as it is. Rather than being forced to take it twice, why not make it scale with your mythic tier though?
Enduring Elixer: Handy.
Fickle Attack: It works out to a half a point of damage for each d6 in exchange for more than doubling the time it takes you to roll and add up your damage. Not worth the hassle.
Improbable Prestidigitation: Lots of fun. Swipe the amulet and make it vanish. Hide your daggers and smaller magic items as you're infiltrating the prison. And so on. I don't really see the need for the Sleight of Hand check though and it's one of those things I wish would scale with your tier.
Itemcraft: Maybe someone else can see how a 1-5 boost in caster level is worthwhile, but I can't. And what charged items are so valuable that they'd make it worth it to use your mythic power to fuel them?
Majestic Countenance: It fits well enough.
Path Dabbling: Clearly the best path ability ever, not much else to be said.
Ranged Disable: Useful and full of style.
Supreme Stealth: The fact that those senses can make your stealth useless in the first place is harsh enough. Being forced to take this 4 times for full coverage is just painful.
This Might Just Work: Useful enough, except for the whole 1/day or mythic power bit.
Unwavering Skill: It's okay.
All in all, these feel more like rogue tricks or alchemist discoveries rather than MYTHIC powers. In my mind, a mythic rogue should be able to slip out of a forcecage, empty a king's treasury or a dragon's hoard like a magic trick, run along water, walls, falling debris, or even a hail of arrows with ease, and steal thing's like a wizard's name or a dragon's heart without the target even realizing.
In more specific terms, I'd like it if the Trickster had more options that focused on mythical levels of agility, deception, and thievery rather than this kind of weird focus on slightly boosting skill checks and using consumable magic items.