I'd personally like to see two things happen.
1. More average MP regen (10 mp/4 sec is fine, 3-4 is a joke, but personally I'd like it to be as much as 1% total mp). The mage dying not because damage is over MG, or because MG forgot to be put on, or some other issue is fine. Dying because "Oh crap I ran out of pots" is laaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaame.
2. I'd like to see puzzle bosses. Ones that involve a strategy to beat (Zakum is sort of this way, having to take out arms so they can't renew the others, but still kinda not what I mean). Pretty much all the bosses are tanks, and either heavy hitters or hp sponges. Stuff like hit the weak point, break the armor with X technique, back-attack him, knock it out of the air. I mean I used a strategy to win the 120 job bosses (since they kept stun killing me and reducing me to 1/1) but it was more a matter of my priest being not really a heavy hitter and having to use a lot of tricks to manage the solo battles.