One problem I have with this game.

[Khalithar]

especially as a healer you see the same debuff icons in your group list again and again but you don't know if you can dispell it or not.

Oh man, I saw this issue a lot with people trying to do Odin, once I told groups to dispel the +damage taken debuff to the MT, every kill became a whole lot easier because his damage was easily managed. Some kind of special symbol around removable debuffs would be nice, maybe some kind of effect to tell you "this can be removed."

[Kallera]

he actually is doing a divebomb. but he is really slow, flys over the arena to the mark and attacks everything under him...

Its more a bombing run than a dive bomb. I was making fun of it so much the first few times I saw how slow it was.