There are at least three configuration files in the game folder, two
system.cfg files and
default_system.cfg. Which one is actually used by the game?
game.cfg in the respective language folder appears to only store keybinds, which can be modified in the game anyway.
Far Cry suffers from severe texture pop-in and delayed texture loading — draw distance can be increased to a certain degree by raising
e_vegetation_sprites_distance_ratio value. There are some other settings such as motion blur which can't be disabled or modified in-game.