Here is my inventory feedback after 150+ hours.
It's just the worst part of the game, or rather the most painful/tedious one. You get so much stuff if you just go vacuuming everything like I do but managing inventory is such a pita, and here is why and maybe some potential solutions:
Bags, pouches: 1. You cannot access them from the vendor screen. So all your vendor stuff has to be just sitting there until you can clear it. Annoying but you play around it once you know.
2. There is a "custom" option in game once you right-click a pouch/bag but it does nothing (at least for me) I was hoping this would allow you to rename any sort of container you carry or stash in your camp. I have several bags per character so I distribute the weight accordingly but I end up opening the same pouches 3-4 times because it gets so confusing.
Inventory/ Camp chest UI: While managing my camp chest ( I have a tons of barrels, fancy chests etc in there so I can organize further), I would have my inventory open on one side, the camp chest on the other and so on. Opening a new chest would cause the chest window to open behind the inventory window, which is so annoying as you have to drag away everything almost all the time. A first decent solution would be to make every new chest window to open up on top of everything that is already open.
You can only expand your storage containers from top to bottom and not diagonally. Why? It makes managing each individual container so much harder
Moving thins around/retrieving things: When moving things around in the inventory (most of the times trying to place them as I would want them to be), it's rather common that I end up placing a full bag into another by mistake, instead of them just switching positions. Maybe switching containers around should be more feasible, as of today I have to play tetris to be able to move them.
Same goes for all containers in my camp chest. And on top of that, If I want to open something inside the camp chest, you need to right-click, then open (and lets remember it will open behind your inventory window so you will have to drag windows around) It makes the process so slow and painful. I would make it that for stashed containers, if you double-click them you open them and if you want to retrieve them, then maybe right-click into pick-up item.