Or would that be too much to ask for?
So that, for instance, the quick bar at the bottom screen wouldn't take up as much precious screen space as it does right now. If you can't hide it like the other HUD elements (any particular reason why that is?) then at least you could scale it (and the rest of the HUD) down by factor 0.5x or something along those lines.

+1
Not only the HUD but also the UI in general could really use scaling option(s). Things like different font sizes, icon sizes, and so on. Would definitely make the consolish look and feel of the HUD/UI a little more bearable, especially on UHD resolutions and beyond.

Never mind, suggested something and it didn't work

Scaleable UI is never a bad thing. I wish a lot more games had it actually. Count me in.

Smaller (or adjustable) and a bit closer to the edges / corners of the screen would be nice to make it less obtrusive.

+1 to these suggestions. I like my screen uncluttered and at high resolution we shouldn't have such massive elements.

Agreed, I guess that's something they can work on on the side for a later, more content-heavy patch.

Wouldn't mind to have that option too.
Especially for the quick bar which wouldn't be as intrusive as it is now if it could be knocked down in size a bit.