I say no. Mayweather wouldn't have moved half as much as Rigo did, therefore there'd be more action, and Pacquiao would have success because of so. Not nearly as one sided a fight.
Rigo accepts Donaire's demand for blood testing and then proceeds to put on a boxing lesson while proving he is a clean fighter.
Yes, but more likely that Pac gets stopped and no KD for Pac. FMJ is far more offensively minded than Rigo. I also think Pac's defense is not as good as Donaire's. I also think Pac is far more offensively minded than Donaire. It adds up to more opportunities for Mayweather.
As many people eluded, Floyd takes a close UD. Maybe something along the lines of 8-4 or 9-3, with many rounds being competitive. I just don't see manny being able to keep up with Floyd's size (height/reach advantage) as well as his defensive prowess and all around skills. Floyd would've been in good control by rounds 5-6. The fight ends with a few late desperation surges from manny, but ultimately Floyd stays out of harms way to win a fight full of clinching.