Crash on startup (mac OS 10.10)

First post, so please forgive any classic blunders. I haven't found success with either Google or a forum search here, so posting away...

My friend recently purchased TS (via Steam) so that we could play games at a distance, standard fare. As of yet, I haven't been able to get the game to run properly: it loads the Berserk logo (w/ audio), goes to a splash/load screen, then crashes before seeing the main menu (repeatedly verified, at least a dozen times now with no successful instance). It's probably worth noting that the game loads at a weird resolution: the computer is 1280/900 (if I remember right; or something close), but the game loads in windowed form about 1/2 screen tall, 1 1/2 screens wide (I can pull it over a bit before the crash happens).
Attempts I have made:
-verified game cache
-updated & restarted computer
-uninstall/reinstall
-force launch options 800/600 (per the Game Issues link, set the options but it didn't change how the game loads- still too wide).
-checked disk space- as far as I can tell, there's plenty

Attached is the most recent crash report (it's been the same error repeatedly). My apologies if anything comes out strange: macs are not my forte.

Thank you for any time and effort in this matter!

Hey there, sorry for the delay and thanks for all the info. Have you updated your graphics drivers? And can you go into your graphics settings and make sure it's set to quality and NOT performance? You can also try adding -fullscreen to your launch options and see if that has any affect. Let us know and we'll see how we can continue to help.