There are few problematic/weak talents in the rogue talent trees:
Subtlety
Heightened Senses: Increases your stealth detection and reduces the chance you are hit by spells and ranged attacks.
The stealth detection part is problematic, because it makes all other rogue talent trees weaker options to spec into because when rogues do not put points in this talent, they will lose the stealth war and thus are at a significant disadvantage against rogues who have put points into Heightened Senses.
Solution: Remove stealth detection from heightened senses and replace it with something less game breaking. Other solution could be to change the location of this talent to tier 0 - 2 so that other specs would have easier access to this talent.
Assassination
Deadened Nerves: Decreases physical damage taken by 1/2/3/4/5%.
Overall this talent is too weak to put points in. The only reason why any rogue would go this high into Assassination is to spec Mutilate for high damage output. However, in order to have points to put in Deadened Nerves, the rogue would have to compromise on some damage talents, which is not an option due to how weak this talent is.
Solution: Buff the existing effect with -1/-2/-3/-4/-5% critical strike chance or replace it with something more useful over all from mutilate perspective.
Combat
Blade Twisting: Gives your Sinister Strike, Backstab, Gouge and Shiv abilities 10/20% chance to daze the target for 8 seconds.
The talent chance to proc is weak at best. Sinister Strike, Shiv, Gouge and Backstab all cost +30 energy and it takes minimum 4 seconds to regenerate the energy back form these abilities. In other words, this ability procs about once per 20 seconds of combat, which makes it too unreliable talent to rely on for slows.
Solutions: Increase proc chance some way or introduce additional effect to the talent. For example, damage increased vs. dazed targets 5/10%.
⌠sweet.