Mez - Try setting your MezRadius to something lower. 50 is the default. This might be making KA scan a lot of mobs if you're in a tight packed area.
debug - Could just be the mez radar running to look for nearby mobs between casts. When running KA, type "/debug on" and you'll get more updates in your MQ2 window about what KA is doing at any time. See if you see any msgs during the DPS cast delays. If your tank can handle it, try turning the mez section off for awhile and see if you get faster DPS casts.
Debuffall - Try setting this to =1 and see if it improves DPS. =2 is a stronger setting that places more emphasis on your DPS slow/tash casting. Probably not your issue, but worth checking.
Conditions - These do slow down your CPU a tiny bit, so you can remove some that aren't needed. Again, I think this wouldn't be a noticeable slowdown, but worth checking.
DoTs - If KA casts a DoT it will also handle not recasting it until it wears off. If you might also cast it from another section like Burn or AE, then yeah you'd want to check if the mob has it first.
edit: The conditions don't seem to match the DPS entries for a lot of these. Maybe check them all to see if you're using some older ones that you meant to edit?
Debuffall conditions - KA will handle the checks for things like "slow" or "tash" automatically. Check these two DPS items & conditions, looks like maybe you had older versions and they no longer match. DPS2 is casting Tash but the condition is looking for specific slows. DPS3 is a slow, but the condition is checking for a dot.
Code:
DPS2=Order of Tashan|100|debuffall|tash|Cond1
DPS3=Slowing Helix|100|debuffall|slow|Cond2
Cond1=(!${Target.Buff[Dreary Deeds II].ID} && !${Target.Buff[Turgur's Swarm VI].ID})
Cond2=(!${Target.Buff[Deluding Constriction].ID})
KA will handle the slow/tash check (any tash/slow will be checked) if you use debuffall, so they can just be this:
Code:
DPS2=Order of Tashan|100|debuffall|tash
DPS3=Slowing Helix|100|debuffall|slow
Mindslash/Sunder Nukes - These two main nukes are checking for dots in their conditions:
Code:
DPS14=Mindslash|96|Cond3
DPS15=Mindsunder|95|Cond4
Cond3=(!${Target.Buff[Mind Tempest].ID})
Cond4=(!${Target.Buff[Strangulate].ID})
So make those with no conditions:
Code:
DPS14=Mindslash|96
DPS15=Mindsunder|95
Those should help out. I'd suggest you give your whole dps/conditions sections a once over just to see if there is anything else in there you no longer need.