What will happen to the effective time for time limited items?
The effective time will progress while you are logged out.
What are avatars? What are the differences between avatars and equipments?
Avatars are items that have no effect to the status and are for the enjoyment of dressing up characters. Equipments, on the otherhand are itmes that enhance the characters abilities and have effect on the status.
When you have epuiped equipments and avatars in the same area, the graphics of the avatars will be shown preferentially.
The skill cores that I received when changing jobs (Fighter:Full Swing Mage:Vanse Gunner:Magic Steel) broke. Is there a way to reacquisit it?
You can reacquisit it by using the alchemy function from Anna in the village of Merida.
Alchemy will be added in the conversation menu of the corresponding NPC by finishing specific quests.
For example, in order to add the alchemy menu, for the NPC Anna in the village of Merida, you will need to have finished the quests "Keeping the Plain Safe" and "Collecting Accessory Materials", for the NPC Leeze in the Almerie plains, you will need to have finished the quests "Keeping the Plain Safe" and "Medicine of Leeze 5".