Except that True Seeing and See Invis are counters to blinking, and those are substantially more prevalent and easier to get than Blindsight "and the like" by which I mean, just blindsight, because there are no other extra sensory modes that prevent enemies from being flat-footed at all.
Blind-Fighting feats. Which is also doable by any enemy with the martial flexibility class feature. There's feats, features, and items that let people see through smoke or clouds as well. You also missed the part where this build requires the rest of the party to also invest in obtaining sight.
See now this, is an actual explanation. I mean, it's weird, because the only combat utility provided by UMD is wands of Grave/Golem/Plantstrike which the Rogue gets natively, because everything else UMD does is decidedly out of combat or absurd TO nonsense, but this at least counts as an explanation.
Wow, you are bad at this. Wand of Obscuring Mist, Scrolls of Expeditious Retreat, Wand of Blistering Invective (if intimidate heavy), Scroll of Walls, Scroll of Summon Monster, Scroll of Stone Shape, etc. etc.
I don't understand that one at all. Bolt Ace is just Gunslinger but uses crossbows instead of guns. From a quick read, it seems weaker than normal Gunslinger, since it has to spend Grit to do touch attacks. Is this assuming some sort of spell-storing bolt antics? Or is one of their deeds deceptively good?
It's because Bolt Ace doesn't need to invest as heavily as a regular Gunslinger into making their weapon of choice functional. The regular Gunslinger is complete shit at starting levels. But come to think of it, Bolt Ace is probably still a Tier 5.
Also, Gunslinger being below T4 to begin with is dumb. By mid-level, Gunslinger reliably kills most things that aren't specifically made to counter them. Far away? Deeds for that. Miss chance? Deeds for that. DR? Feat for that. High touch AC? Good fucking luck, you're going against someone with full BAB + Dex primary + enhancement bonus; Monk, for example, is not nearly enough.
Even some of the specifically anti-gun spells/items are woefully insufficient - 3-4 more points of AC won't help when the Gunslinger would hit you on a -5. And Bullet Magnets won't last a single round, even if you make them out of Adamantine.
So is the rating based on "with no items" or "not at all optimized" or something? That doesn't seem very useful.
My problem with the Gunslinger is that he sucks a ton until he gets going and then all of a sudden he murders everything. And for the most part, his class features as a Gunslinger aren't really contributing to his power. That just comes from the gear, really. A Trench Fighter or Savage Technologist Barbarian would outperform that easily. Even without dex to damage, a Fighter, Ranger, Paladin, Bloodrager, Sohei Monk, Slayer, Vigilante, etc. all do it better. Yes, the build is potent once it gets going, but the Gunslinger class itself contributes almost nothing. I'm not going to list Commoner as T3 or higher just because of WBLmancer builds either.
The biggest thing that makes the Gunslinger look so strong is that it strongly encourages you to abuse a highly potent combat option, but in reality you never needed to be a Gunslinger to do that, and you are probably worse off for picking that class to do a firearm build.
Edit: On further inspection, what is up with this whole list? How is the Slayer's ability to "do a bunch of damage" and "be good at skills" a tier higher than the Rogue's ability to "do a bigger bunch of damage" and "be good at slightly more skills"?
Eh, I wasn't too sure about the Slayer, but iirc it was the d10 hitdie, the added strong fort save, the full BAB, the ability to get attack and damage bonuses to targets, and his talent pool (which gives him Ranger Combat Style - ignores prereqs - in addition to bonus feats from Combat trick talent and Feat advanced talent). It's trivially easy for a Slayer to make a two-weapon throwing build that uses a Belt of Mighty Hurling, for instance. Simply put, the Slayer does not need Sneak Attack to ruin an enemy but he can and he will probably land more hits while he does it too.
Same deal with the Ninja.
Ninja gets an extra attack and can give himself invis and greater invis as a swift action. Anyway, they're on Tier 5 now.
Also, not convinced Investigator is T3; yes, it has extracts, but I've never seen a build that was very impressive for it.
It's probably a weaker alchemist, really, but it still has the Alchemist's action economy abuse and mutagens while adding half his level to attack and damage.
And Unchained Monk is not T6, come on; it may be a Monk but it can deal damage moderately well, enough to hang out with Fighter and Vanilla Brawler at least.
Any decent Fighter picks up a Bow or goes TWF thrower and is actually quite effective while doing so. Archetyped Fighters get sillier. The Brawler easily performs a Flurry with Shuriken and if he does go for unarmed strikes, he can add the Brawling light armor property while collecting more attacks than an Unchained Monk. He also has Martial Flexibility to screw around his feats and keep him relevant more often. The Unchained Monk cannot compete well with that. In fact, his special Flurry of Blows prohibits him from getting bonus attacks with TWF (unlike the 3.5 Monk whose FoB the Unchained Monk is clearly mimicking). A vanilla Monk would perform better with shuriken by getting both a full FoB and a bonus attack through his ki pool. To get his style strikes the Unchained Monk needs to use unarmed attacks too. And the unchained Monk's melee still gets to choose between doing damage (str) or having AC (dex and wis). Class is still stupidly MAD.
And some of the Monk archetypes reach T4.
Sohei and Nimble Guardian, aye. Not so sure about ZAM. That one feels more like a high Tier 5, competing with the Fighter.