Regarding Open Mic Settings: I got device errors when trying to use Desktop Mode. With Line In set to my headphones i could hear the music both from my music player and the game with a bit of delay simultanously. To get around this i configured Pulse Audio to send the output of the music player to an unused device that weren't my headphones and let the game access that one.

With a dual monitor setup the game for some reason believed my non-primary display was in fact the primary one when switching to borderless fullscreen mode.