a) graphics glitches. The control panel keeps blacking out on the main screen (except for npc portraits), and glitches on the inventory screen as well. Not sure what's causing that one, unless it's an issue with the opengl drivers.
Any suggestions on the other issues? The audio isn't game breaking, but the video distortions are pretty annoying.
I'd wager that, as you have already surmised, it is indeed an issue with your OpenGL drivers. You could try to disable 3D rendering as a potential workaround. I use Void Linux currently, but I've witnessed similar rendering artifacts with the BG2 engine for some time (as in years) across various distributions.