ToDo

TOP

Split castle model in more parts to apply Occlusion Culling for better performance
Apply castle interiors from https://github.com/OpenHogwarts/models . Maps/Blueprints at https://github.com/OpenHogwarts/Documents/blob/master/Blueprints/hogwarts_randwulf_map.jpg should help.
Improve/Fix Bag panel style
Improve/Fix Seller panel style
Get more Hogwarts castle interiors and other movie scenarios models

Get more monster & human/student rigged models to set them as NPCs (fbx format)
Place NPCs all over the map
More Quests. Even just scenario/idea we could then implement. If someone comes on board with no programming knowledge we could add a quest editor (there is not enough NPC and object to add it yet)
Fill the library with fan fics books and interesting things about hogwarts
Some sort of minigame like chemistry/potions one? (player must have x sort of items and combine them in a very specific way (that he could read on a book) in order to create a potion)
Skills system based on character level
More attack types
Character customization