The current values are completely unparalleled mainly due to the fact that ARMOR soulcraft options allow evade bonuses by % while not allowing aim % bonuses. Why should this be the case? If you allow soulcraft options on armor to give aim% and evade% a lot of the evade vs. aim issues would be squashed. Personally, I could reach 600 aim on my invoker just with that update alone. And it would be justified, because I spent a ton on this game just as a lot of evade stacked ninjas have along with other classed players.
I see where you're getting your reasoning, but I have a feeling that changing armor pieces so that they can all receive +Aim Rate % on them would make evade almost pointless -- simply because anyone who takes PvP seriously is obviously going to get that option on all of their gear, making it so that most PvP-centric players would easily be able to hit enemies with even the highest evade rate values pretty reliably.
The mention of your invoker with 600 AR is itself a good example... If invokers can hit that AR, just imagine what some of the other classes (the ones that get AGI as extra options and set bonuses for equipment, like sentinels and destroyers and savages) could accomplish. I admit I haven't been around much lately to get a good sampling, but at least in the past couple of weeks I have rarely seen characters with more than 500 evade, which would be a 100% hit rate for a character with 600 AR.
IMO, evade rate *should* be at least somewhat easier to stack than aim rate, because the use of evade to (at least partially) avoid damage and debuffs is one of the defining traits of some of the classes you have mentioned (especially ninjas). I'd venture to guess that's part of the reasoning behind the former developers' original decision not to include +Aim Rate % options on most armor pieces: They wanted evade rate to be a considerable benefit for the classes that can use it effectively.
That's not to say that evade rate, in its current form, isn't overpowered, because it is. But as I mentioned above, I feel that if you nerf it too hard, you're going to make it obsolete -- and, by association, the classes that rely heavily on it for survival in PvP will suffer a considerable loss.
Elements have completely redefined pvp. Allowing even level gaps to be pointless. The hardest hit players are the most stacked ones, having over 20k pdef or 15k mdef is pointless as element damage completely ignores any damage reduction other than elemental resistance. Player defenses become paper and everyone is out to kill or get killed in a matter of seconds.
I agree, element damage is a big issue that needs to be addressed soon. I've seen invokers with element cards and accessories and nothing more than Zauharant weapons tear through +20 Elga set-wearing paladins in a matter of seconds. That's outrageous, and from what I understand elemental defense isn't the answer -- at least not in its current form.
Personally, I feel that elements never should have been enabled in PvP to begin with. It overcomplicates the already complex system of stats, values, %s, etc. that already play roles in PvP. And even if elemental defense were a viable counter, what are you supposed to do -- have four different sets of elemental armor, each infused with a different element, so you can counter each type you might face? Ridiculous. Besides, you can't swap equipment easily in battle, so that's not even a good solution. Sure, there is a "5-element resistance" attribute, but it's seemingly incredibly rare on socket cards, making it difficult to stack effectively ... and if you make it easier to obtain, most players will likely go for the 5-element resistance and completely ignore the base four, making them more or less pointless.
I think until a better element system can be devised, elements should have no effect on PvP whatsoever. The PvP system already has enough balance issues as it is, without throwing that into the mix -- especially since it really adds nothing meaningful to PvP other than additional damage.