For the first question,Ali would have won,he was too good at sniping away,and letting his opponent make their own mistakes,as time went on,it became very apparent with Mike,that if you frustrated him,he'd make plenty of mistakes. And Ali would have driven him to distraction.
As far as a bout Id love to see,prime Manfreddy vs prime Mancini,two pitbulls of a fighter going hammer and tongs for however long it lasted.