The alchemy system should be expanded, with a lot more items and things to craft (more potion types, scrolls). But also with craftable and even update-able items.

I also have the Idea with craft items in different levels, for example you level 1 2 and 3 iron ore to upgrade to your weapon.

The other thing is, that later in the game the inventory gets full very fast. This will go even faster with more items. Maybe add more inventory slots in total, but in categories like: craft resources, usables like potions and scrolls, quest items and other stuff.

I got my inventory even so full that I managed to fill the whole buyback on a few traders...

Another idea is that you can do basic stuff like crafting portions and maybe scrolls with your crafting device, but you need to go so someone specific, who is crafting special types of items or upgrading stuff using your resources...