Regarding the Claim System:
I think the claim system in AION should be like FFXI. The person who hits it first should get the mob/exp/loot/etc. Make it where if you don't do consistent and steady damage or Dot per Second (for mage or ranged attackers), the mob should go unclaimed as well as the loot/exp etc, also it should go unclaimed when you die. This would make it good for both melee and mages/ranged attackers so noone really has an upper-hand at mobs etc.
Regarding the Abyss:
Since everyone brought up the issues with claim system in AION, people complained about how a claim system would ruin the Abyss. I have a solution for this: Make the Abyss not only Elyos VS Asmodians, but also legions against legions as well. So, if one legions claims a boss mob and does consistent damage or w/e, if the other legion believes they are stronger, they can attack this legion and take the mob for themselves. (Which in my opinion would solve the issues against claim system AND make the Abyss more competitive and interesting). Also, make it where you can't attack your own group/alliance/legion mates.
Also I heard there's some stupid language barrier between the different races, please also remove this. What's the point of it?