Re: Randy Orton's gimmick isn't for sell.
Orton was a good heel when he was cheating his way around with Legacy but even then his in ring presence just makes you love him.
He is not having a lot of mic time but i suppose this is partly because of his "no bullshit-serious-mental" persona. I am pretty sure he could provoke a lot of boos with the right script but it would ruin his gimmick if he suddenly started dishing the fans like Punk or Jericho. His persona works better with cheating or bullying ... not with the mic.
as for Orton as top face? it definitely can be done .... just a minor tweak with his gimmick and there you go. Not mental anymore, just bad-ass and without any friends/allies in the WWE. It is just up to the WWE creative to do it right (this is the hardest part) ... people evidently like Orton whether he is a heel or a face. The guy works matches like so few do today. He may not be high-flying but he knows how to take a beating and definitely knows how to deliver one.