I agree with RJSlow.
2. If you got skillpoints from each of your friends it would start a friendlist race among players. It would also greatly affect the game balance. Improvement through training and matches would be almost meaningless. Also I have seen friendlists of 1000+ on other facebook games. That´s 1000+ skillpoints per day. Do you really want this?
3. Messages would be nice but it had to be friendlist only to not produce lots of trashtalk.