Thanks for the suggestions, I'll add them to the Requests list. I'm not sure whether we can implement all of them or when.
Note that you can already make all of these yourself with a bit of custom code. Here are some ideas if you wish to explore.
1) Use a custom Item Action to start the drag and drop. Check out the Move Item Action that lets you move Items from different slots.
2) Create an Item Category for each Weapon Set, or create an Attribute that defines the Weapon Set of your Weapon. Then in a custom Equipper script deal with Weapon Set stat bonuses
3) Add a float Item Attribute for durability. Reduce the value when the item is used. Once it reaches 0 destroy the item or prevent it from being equipped/used. Then add a functionality to increase the weapons durability.