alot have already been mentioned. but these are a few things that comes to mind.
Castle Siege should have more ''stages'' when the server progress, to keep motivation up. maybe something like a weekly rotation on drops on erohim, so lets say on cs week 9 he has chance to drop xxx but only one kill per week, and make him actually feel like a boss
Remove Jewels from OB +5 but reduce chance for ob +5 to drop
Remove Horn/mats for fenrir from ob 3/4
Crywolf is a dead map, bring back fenrir farm(with decent drop rate)
Let people with murder status enter events like cc etc.
Class vs Class duels or stage Arena. you fight random opponent and if you win you move on to next round
Helpers, where did they go? should have been added long ago to help newbies
Economy: Way to many jewels around, when people offer 500/500 for items its getting abit to much.
Remove spots with Hydra,Ice Queen,Gorgon, Bil of balrog etc, and make them have a chance for exc drop as they have on newer versions(respawn time high and random) perfect for newbies to stumble onto and reciving their first exc.
Make RF.,MG,DL same lvl for warp/events like other classes
Increase days Vip last or release one that last longer.
On battle maps let us pk same gens during events(Medusa,queen) (Murder status )
Increase points for CC win. a win should always give more score then just farming mobs in my opinion.
Increase cs damage for later game, at current stage I think all can agree its like a wet noodle contest.
Budges in more maps(not more budges, just more maps to spawn in)
Make Imperial alot harder, should need a decent party, not filling slots with alts
Remove Fenrir/Unria/Dinorant from Arena
//Zutto