To me, it might be points 2 and 3 that I would rate as more important, among 1--4.
For 2, I don't know about "how", but I'd like not to have a slow-down every time I open a management screen.
For 3, so many people have requested this so many times : there isn't a lot of interesting gameplay in tediously checking all the bodies. Just meaningless clicks. Tabletop experience : "we loot the bodies and search the room". BG3 experience "I inspect body 1. I inspect body 2. I inspect body 3. Now I inspect container 1 ...". Of course, this is not incompatible with a reflexion on the number of containers, their emptiness, or the amount of garbage/clutter they contain. There will always be bodies.
But I feel the most important point would be :
5. Register our clicks. If I click on an item to drag it from one character's inventory to another, I too often find out that the item wasn't dragged. This issue with sensitivity/registration of clicks also affects selecting a different character, especially in world-exploration mode.
