Just to clarify...
there is friction on the flat parts of the course, and only the flat parts. the problem is that if the ball is on a hill, no matter how small the angle is the ball continues to roll and even speed up. my suggestion (if i can offer one cause i've never worked with a physics engine b4) is to have the ball continue to slow down on any hill less than 15 degrees. Also the golf ball should have less bounce on the grass when being shot with less than half power, i noticed that it sometimes took three or four bounces to finally stop at half power. and i scored a 39