I do have a prc file in the game directory, I believe–albeit named “game.prc” rather than “config.prc”, I think. It seems to respect some settings from that file (such as making the window non-resizable), but not the window-size setting. 
Regarding the errors, what you say is entirely possible: I’ve had a terrible time with graphics drivers under Ubuntu, both on this machine and another machine that had an integrated Intel chip, as I recall.
(For example, the shadow samples don’t seem to work properly for me. For whatever reason, the shadows used by wezu in Avolition do seem to work, however.)
(My driver trouble in this case might be due to having, I think, a slightly older graphics card–an ATI Mobility Radeon HD 3650–for which I believe that support is somewhat spotty. At the least it’s working rather better than did Ubuntu’s support for that integrated Intel chip, at least in the versions of Ubuntu that I was using at the time.)