Here are my suggestions:
Make gaming experience rewarding - gifts depending your level (10, 20, 30 you get the point),
Filter the chat system (Shout is being abused into a social hang out,
Daily Quests or just repetitive quests in killing mobs is good for grinding - it’ll be if the major factor of this game is grinding . Give average amount of exp when quest is done.
Remove level restriction in quests or tone down the level - one of the reason we grind.
Party Event should only be for party members. Do it the same as boss fight, put us in a different dimension away from local mobs, and random players.
Make monster untargetable if you hit it first so kill stealing is prevented
Raids. they’re tons of fun.
Make it easier for us to add a Party Member by searching the name.
Additional tabs for chat system - seeing the normal tab is being abused by shout system I recommend adding additional tabs like System, Shout/World, Bargain.
Give hint the location of recipes ingredients make the description hinting what monster or place of the materials. Or just make the materials like Coryleus Horns is dropped by < Pawndel? Add it in journal or the description either of those.
Gain exp by exploring the area - seeing the world is pretty huge, and the areas why not? Slight exp gain, and the more you explore you’ll get a title achievement “Explorer”.
More Headgear/ Accessory mobs/boss loots Either crafting the recipe or droppable gears like based on the boss. eg. Muschcaria Hat
Cards I’m hoping the cards aren’t only for bosses, but the regular monsters!
Note - This is my opinion and I could be wrong, so It’s okay if you guys don’t fully agree with me, then give out your opinions or better suggestions. I might add more or edit later on.

) =P .