Yeah keyboard is definitely a challenge with this game. I know a lot of us use a racing wheel like a Logitech G29 or G920. If you don't want to spend that much money though I would suggest at least getting a controller (Xbox or PS4). Canard control is key in this game to going fast and a wheel or controller will give you much better control of it than the keyboard will.
As for the buoys;
Orange/Green = inside of the course
Yellow = entrance and exit of turns
White = outside of the course
White with checkers = Start/Finish line