Here some ideas for the inventory:
1. Provide a AllInOneInventory (one big bag showing the content of all bags),
support for inventory/bank/house
2. Provide an option to show the inventory contents of alt's (I can provide a UI Example from a different game if needed), though the items there could not get
manipulated of course and would be "read only"
3. Provide a sort option (after armour/weapons/crafter items/recipes/...)
4. Provide a fullstring search (only items matching are shown in the inventory)
About 3. and 4. I can provide screenshots of another game, how this may look.
5. Provide Outfitter functionality (Outfitter is a WoW Addon, I will explain how it works):
- When you click on an equipment slot on your character page, a list of "fitting items" from your inventory is shown left or right of the slot. By clicking one of the items you can equip it, without having to search for it in the inventory
- You can define "outfits" for special occasions (I can provide a UI Example from Outfitter, if needed) and then switch to them by a simple mouseclick.