PEDs probably. If you thought Mayweather's running was bad, never watch Andre Dirrell's fight with Carl Froch
Maybe if Pacquiao had the boxing skills of Carl Froch he would be able to nullify the running and win like Froch did with Dirrell
Yes. He had to make two goes at making weight, Froch is slow as hell, and he is the type to get juiced up.
He probably was strong enough to hold onto Froch for dear life and bigger and faster hence his struggle to make weight and world record distance covered.