Hi! I've got a couple of suggestions.
While playing solo with 4 characters in the party, inventory management can be a little bit tedious, so here go some of my thoughts.
1) I believe that adding a "batch selection" feature would improve this drastically, so players can select many items and perform actions on all of them at the same time, i.e. moving all those weapons collected by your main character to a specific character's inventory.
2) A search box could be added to the filters area, in order to search for a specific item.
3) Backpacks, chests and pouches are useful to store many items and provide "user-defined categories", but adding things to them might be bugged. When having the container opened, and dragging an item, a dotted outline is shown around the container item, suggesting that dropping the item on top of the container's icon would store the item inside, but that's not the case. On the same note, maybe we could have the ability to rename these containers for easier and better organization.
3.1) Equipment stored inside containers (backpacks, chests, pouches...) should be shown when clicking an equipment slot in the Equipment window.
4) The inventory window could have the keyboard shortcuts/actions labeled at the bottom, i.e. Split: Shift + Drag, Send to Wares: Shift + Click, and so on for all the options.
5) I think the right-click drop down menu for items inside the inventory window has a pretty but slow animation that could be sped up a little.
I apologize if any (or all) of these had been discussed before, or even planned into the game, but these are my thoughts after some hours into the game.