Guild Wars 2

monster behavior and stats:

• The monster behavior in GW2 is very static, which doesnt fit to the rest of the games fast combat.
  Right now, monsters only have those hard hitting, well telegraphed attacks. Some faster hitting, attacks with lower damage between those strong ones could add allot to an faster combat. When the monsters then start to evade and step out of AoE damage. This would be an really interesting and challenging content
• Defiant needs to go, because with defiant control builds are useless. I know, that without defiant bosses could be hold into a stun-loop, but to compensate this I would include a rage mechanic, when a boss gets interrupted to often (3 times in 10 seconds), he will gets enrage. Which means immune to CC, faster and hard hitting for a 20-30 seconds duration.

These changes could then lead into interesting boss mechanic, that requires team play and coordination. Some interesting suggestions were made in this thread a while ago:
link

fix broken/bugged/unfitting skills:

• On the top of each class forum, there was a thread with bugged skills, that dont work as intended (or as described in the tool-tip). Most of them need to be fixed before balancing a class. It makes no sense to balance something, that doesnt work as intended.
• Some classes lack of underwater skills, for example necromancers elite skills

I know this is a lot, but with all these changes or at least most of them, we can start on balancing classes equally over all 3 game modes, without splitting the skills. But balancing should be started at the traits of the classes:
Necromancer for example have a lot of builds, that looks good on paper, but cant be played because of bad implementation or to low numbers.
blood magic trait line for example: 47 health on crit doesnt help out there in the world.