I think his charisma is 3.5 years past its expiration date. And his spectacularly negative campaign will underscore the fact that he is not a nice guy, first impressions notwithstanding, that he is merely a Chicago thug with a funny name and an uncommonly interesting background (as far as it's even known).
So I think putting a recognizably strong intellect on the ticket is the right way to go.
Absolutely.
Romney has got to put forward a vision and a plan. It's not enough to say, Obama drove us into the ditch, and I'm the better driver to get us out (because I made a gazillion at Bain and fixed the SLC Olympics). He has to explain why. Figuring out the why has been Ryan's avocation since entering the House.
It's just never going to happen that the general public will lean towards saying Obama is not a nice guy. It would take a couple of Mel Gibson or Michael Richards-style rants caught on hidden camera to make that happen. Obama will not lose this election on the issue of likability and wouldn't have no matter who we nominated. But he can lose it on issues of competence and vision.