Floyd's punch out put simply isn't there. Landing a few sneaky cheque hooks and hard rights will not get the job done against Pacquiao. Pacquiao is a whole different beast to Canelo and Maidana and will overwhelm Floyd from the opening bell. Say what you want about the Marquez KO loss, you give a supreme boxer like Marquez 4 opportunities to get the job done, he'll eventually get it done. Pac wide UD.
I agree, Floyd simply wont be able to keep distance as Pac has faster feet then Floyd, Pac will constantly close the distance and get his shots off, Floyd will get hit more then ever in this fight, Mayweather simply has to throw more punches and trade with Manny to win.
Pot shots will not get the job done. Mayweather won't be able to tie up Pacquiao because Pac won't give him the respect. Pacquiao will annihilate Mayweather.
I think against Pac, Floyd's punch output would even diminish more as his shoulder roll will not be effective. It means his counter will be less effective as he will rely more on high guard.