When you have the def/aggr slider all the way to aggressive why exactly does it increase all of your initiatives with the only penalty being to lower your evades? As it is now there really isn't much reason at all to want to use a slider setting other than full aggressive.
Why would an aggressive stance where you try to rush the casting of a nanoformula be better and more efficient...wouldn't you have a tendency to make more mistakes? The speed that you cast nanoprograms should be based on your actual nanoinitiative...completely independent of what your current setting is on the def/aggr slider. That way a casting class such as an NT for example could keep their def/aggr slider all the way to defensive without having a penalty to their casting of nanoprograms...allowing them to gain more benefits from the evades that they have.
At full defensive you should attack slowly but with a slightly better chance to crit due to you taking your time and watching the target's defensive setting. You would get hit for less damage and at a slower rate. When you do finally hit your target it would be for a much larger hit at the cost of being at a much slower rate. Specials on weapons should not be instant attacks, instead they should have to go through the attack recharge sequence of a normal shot or swing. The only exceptions to this should be attacks that are meant to be used quickly such as fling shot and fast attack.
At full aggressive you should be able to attack faster but at the cost of a lower chance to crit and lower evasion skills. Your special attack activation speed would increase but you would have a lower chance to crit since you are rushing through the shot. Take more time for the shot...get a better chance to crit.
Ideally really slow high max damage weapon users would opt for full aggressive setting. Intermediate speed weapon users would most likely use a middle setting on the aggression bar for a normal attack. Fast weapon users would most likely benefit more from a full defensive or near full defensive setting. No matter what setting you chose your nanocasting speed wouldn't be determined by your aggresion slider but solely on your actual nano initiative instead.