Considering that Romney's biggest hindrance was his stance on social issue and his attempts to out democrat Obama on being a democrat when it came to the use of government on spending and economic issues that leads me to firmly believe by a large margin it would of been better to have either Ron Paul or Gary Johnson. Both men would of nullified the Obama's stances on social issues and provided actual real contrast on economic policies and furthered the debate on the role of government in our society along with provided greater debate on the what the role of our military should be overseas, etc.
When they stopped polling Ron Paul v. Obama, Paul was losing on average by somewhere around 8-10 points... and that was with nobody attacking Paul and Obama at one of his weakest points. Not only that but Ron Paul's economic policies that you wish to highlight are in fact enormously unpopular in the electorate at large. (same with Johnson)
While I can appreciate your desire to have a larger debate on your important issues all the available evidence points to Paul losing in an epic blowout. I find it extraordinarily unlikely that Ron Paul would have even come particularly close to Romney's finish, much less actually done better.