I agree that only Michael and Al knew about wacking Freddy....I also agree the Michael would not have had Fredo killed when Don Vito was around, like he said in GF2, "I don't want anything to happen to him while my mother is still alive." I also don't think Fredo knew he was going to get wacked, he was an idiot, he was not "smaht" like he thought he was.....otherwise he would have been suspicious of going out on a boat, alone, with Al Neri.....if he was aware that Michael would want him dead, he would have not gone out on that boat........or would he? Maybe he knew it was going to happen sooner or later, and he was tired of being paranoid about it, and just got it over with.....hmmmm??