because i have been tester into your server Nicolas let me suggest you few things you may change/add..
About Farming
You could decrease the ammount of dropped items from farm mobs at least to throw 5-6 coins per mob...
About other stuff
Erm first about Hero with its skills... If you could change that from current option which is Killing BAIUM to get it maybe you could add special coin where can someone buy with event medals or w/e you can choose for...you could remove some options in achievement npc due to repeated missions etc.. Also you could add vote manager for hopzone/topzone and the chosen reward you want so members can get their reward every 12hours just like autovote reward system, with only difference that they have limited time period to get so...
These are my opinions for the server. Thank you and have nice beginning of it.