It also seems that Hold Breath when using a scope cannot be rebound. Which is very annoying as i've always used Spacebar as my go-to button for aiming. However i cannot press both alt and spacebar without letting go of my movement keys.
And yah, not being able to rebind to certain keys is a problem aswell. I got all kinds of extra mouse buttons that are considered Numpad keys, however these keys are unbindable so i cannot use any of my extra mouse buttons.
Multi-function keys, thats another one that's bothering me. Either you bind your bash key to let you quick melee or quick grenade, but you cannot seem to have both at the same time because they are forced on the same key. I can understand that for button constraints this would be needed for a controller, but i got plenty of available buttons that i could assign.
The auto-lootbox function is something that should be an optional toggle. I've only played 3hours so far and it's been a source of irritation a few times now already. Trying to reload, but nope you open a loot window with a corpse/container you were looking at. Which also comes back a bit to multiple functions on one key.
Overall i do really enjoy Fallout 4, in many ways it is absolutely great. But UI, keybindings and options are just aweful