Restraint (level 77)
Ability delay: 10 minutesEffect duration: 5 minutes
Description: "Enhances your weapon skill power with each normal attack you land, but prevents you from dealing critical hits."
Would use this for zerging when you have Mighty Strikes? No. I can't imagine a situation where the WS bonus would exceed the substantial benefit of 100% critical hit rate.
Consider the implications of 0% critical hit rate for the purposes of great axe WS spam without MS. Then, consider the implications of 0% critical hit rate for Raging Rush (doubtful that the loss of critical hits wouldn't apply to the WS), leaving King's Justice as the only choice for WS spam. Will the trade-off be worth it? I doubt it. If anything, I wouldn't be surprised if the bonus applied only to the first hit of any WS, and I doubt you can cancel Restraint and keep the WS bonus.
The loss of critical hits and actual WS bonus notwithstanding, this naturally favors one-handed weapons relative to two-handed weapons in theory, except that dual-wielding generally sucks relative to using great axe (or polearm when applicable) and one-handed weapon skills not named Rampage generally suck, too.
Critical Attack Bonus (level 78)
(Also Thief level 78, Dancer level 80)Description: "Improves power of critical hits."
If this is like a permanent Brave Grip (estimated 3.5% increase in critical hit damage), it's better than nothing. Technically it's "good," but it's not to going to change anything about how to "play" warrior.
Of course this bonus has to be introduced alongside Restraint, which is likely to be a spurious JA.
Fencer (level 45)
(Also Beastmaster level 80, Ranger level 80)Description: "Increases rate of critical hits when wielding with the main hand only. Grants a TP bonus to weapon skills."
The description and jobs for which this is available seems to imply that the rate increase applies to one-handed weapons only without dual-wield. Now why would anyone want to do that? Tanking!?
It's way more relevant for jobs subbing WAR at level 90 and beyond. But watch the rate increase be like 1%.
Shield Defense Bonus (level 80)
(Also Paladin level 77)Description: "Reduces damage taken when blocking an attack with a shield."
Joke.