I'd be very surprised if we couldn't. I'd expect all buttons to be configurable to most functions. SMS' previous game Shift 2 supported remapping all controllers. Of course that doesn't guarantee anything but if I was a betting man I would bet my house on it
I'm fully on board with paid DLC, I think you get what you pay for for the most part, but my only concern about DLC is paying for tracks. If all tracks aren't available to all people it really impacts open lobbies and organized series because not everyone will have all the tracks. If they could find a way to make the tracks really cheap or free but charge for all the cars it would really promote long term consistency. I don't know the underlying economics of it and it may not be affordable for SMS to give tracks away at this point, but if it could be done that would be great.