Modifying a configuration file is not bannable
You might have a strange resolution that needs change
You might want to disable voice chat as you're sick of the ranty kids
Certain graphical options are glitching due to incompatiblity so you turn them off.
However
Editing files relating to game data are the difference since many can't comprehend the difference
Editting a config file is like adjusting the seat in your car and positioning mirrors etc
Editting a texture file or changing how the game reacts usually is picked up through CRC checks and will deny the user connecting to server and even at times prevent launch on some titles THIS IS CHEATING.
For those not knowing or comprehending swapping out a gearbox for a custom gearbox for a better ratio in a race that requires all STOCK parts that is cheating However Adjusting the seat and Mirrors is not.