You have it right that Macri needs to nationalise his profile, the problem is despite her own wealth, privilege and education, Cris has set herself up as President of the People and Macri is the horrible rich privileged guy that doesn't know what's best for the rest. And it's true, Macri gets the professional, educated, city-dwelling vote whereas Cris gets the rest (obv she also gets some educated professionals as well, but frankly I think a lot of those are tiring of her now too, especially when they took their holidays abroad this year and got slapped with the additional tax). Macri needs to break out beyond CABA if he wants any hope in 2015.
Regarding religion and candidates -- well I'm from Canada where we tend for the most part to try to keep our religion and our politics separate, and I'm also an atheist so I really don't like religion nor references to God in my political figures. However, Argentina is an officially Catholic country and there are still a lot of religious people out there, especially beyond Capital, so here it can be a benefit for recruiting votes. I respect other people's right to religious beliefs, it's just not for me whatsoever, but in a country that does have an official religion I understand that you're also going to get a lot of it in your politics.