Didn't they already come out with their "findings"? The suspension is due to Harbaugh refusing to cooperate with the NCAA as he insisted he did nothing wrong, because Harbaugh is a headache and thrives on being difficult.
If it were anything more serious -- we would have heard about it by now.
As far as UM self-imposing a 3 game suspension -- pretty self explanatory. You or I could coach the team the first three games and UM will still win by a landslide. They self imposed 3, so that if they come back and say it is a 5 game suspension, he will have already served 3 and he would only have to serve 2 more.