Did any of you read the entire OP, or are four sentences beyond your attention span? Obama's approval rating has dropped 10 points since the election, so the assertion that he would do as well or better in an election today than he did in November is asinine.
As far as prognostication about the 2016 election, it seems like none of the erstwhile GOP candidates will do any better at uniting the party than Romney did in 2012. Remember, he was running against an incumbent who used all of the powers of the Presidency to ensure reelection (not to mention Sandy).
Assuming Hillary will be nominated in 2016, who else would be better able to remind people of the foreign policy fiasco under her watch as Secretary of State?
All this being said, the next President will likely have to deal with the explosion of the debt/interest bomb we have been constructing. Only an ideological megalomaniac who wants to complete the transformation of America should interested in that job. On that basis, I'm not sure Romney qualifies.