Off the top of my head, in no particular order
Modern resolution support
I started the game @QXGA (2560x1600) resolution, then I learned you basically have to play at the lowest resolution. Many interactable objects such as doors, switches, fishing rod are only a couple of pixels big and are both hard to see or click. I have to turn down resolution and/or slow mouse speed down to click that one pixel...
Inventory management
In games where scavenging and carry weight is such an integral part of the game. It would really help to have some basic QOL things such as
*total tab weight (Total WT of components, weapons, meds) so you can quickly see what is weighing you down.
*Sorting by WT, Value, New
*Visible Quality of components in assembled items (what gameplay benefit is there to hide it?)
*compare items (green plus arrows, red minus arrows, and difference?)
Reramped detection/stealth/sound
A silenced 5mm kill breaks stealth and enters combat? but I can snipe with a 12.7 from 20 tiles away and they just want to see what the sound was? Why does stealing something undetected = auto hostile? (ex. muties). Misclicking an npc owned item that is right next to npc... can't I get a warning unless I actually take something?
Better combat feedback
I've finished DC and currently finishing the expansion on hard. It is not always clear which NPCS/creatures are armored or unarmored. There are different color shields but I don't care because of EMP. Enemy resistances? Unless they are highly resistant (50+) it doesn't matter just cast/shoot more.
Screen Transitions
I'm running the game off an SSD and it takes longer to load the next zone than jetskiing across it @5x Speed... 3 seconds of jetskiing, 10 seconds load, 3 seconds, 10 seconds...
Pacifism
Right now we can sometimes not be a mass murderer... Why can't I stun/tranquilize to end fights?