Uncertain if this is a known issue or not, but I just took a screen shot with Steam, screen turned black. Game still ran ie could shoot and do other things. But there was no actual screen or anything else.
Other stuff which I assume is known is that the weapon sound effects can be buggy. And the lack of sound effects or voice chatter for Chaos critters and the like. Also when running with the Crusader, not sure if this is known or intended, when swapping between Bolt Pistol/Chainsword and Plasma Gun, the Plasma Gun option, while blocked out, the tool tip is still there if the spot is hovered over.