The big edges that Shane has, as everyone mentioned, is size. I think power is fairly similar, since Shane wasn't a 1 punch KO artist, he KO'd most by attrition. Draw would be a safe guess.
WTF are you talking about? Manny has been KO by body shots. You have a greater chance if you go to the body on Manny. Example he was in deep trouble when Marg got those body shots in on Pac. If someone went to the body more example Shane at 135, Manny would be in trouble. To many fighters concentrate on his chin and not his body.
At lightweight, Shane Mosley was at his best. He had a great blend of speed and power in combinations. He was a great body puncher, and he had better footwork back then. I think Mosley would definitely win. I would probably say by knockout.
Not many boxers in history could beat Mosley at 135, Pacquaio has a decent chance, but not a great chance.