Right now, the biggest issue seems to be the game has zero movement prediction on the server and doesn't trust the client at all when it comes to movement in battles (which is odd given the number of teleporting bots seen around, so there must be some trust but I digress). There is a post here for another online game, Path of Exile which is an Action-RPG (ie, Diablo) style game and the linked post explains how they are compensating for latency; what i'm primarily pointing out is the part on movement prediction and how ARR really needs something like this if they are intending to stick with the 300ms update cycle as well as the tight-timing dodge mechanics.

While this method can induce "rubber banding" when client/server disagree, it seems preferable to the roulette style of dodging we have now and, given the less frantic pace of movement in ARR vs an ARPG, its less likely to rubber band anyway. Yes, it does involve trusting the client somewhat and verifying later, but if there are only 2 server clusters for the entire planet, then lag compensation is outright required to level the playing field.