All these crashes... did anyone else take note that most of them happen when you would get an achievement??? I think that's what's causing the game to crash, it tries to upload your achievement to the steam server and notices you have a trainer, hence crashes your game.
Just food for thought...
If so, would I be right to assume that if we download the savegame of someone for whom this game works correctly and who has unlocked all these achievements, then this game wouldn't crash and we might even be able to play it with the trainer ?