I agree for the most part with your statement, with this one exception (because I know Mormonism) Romney is who he is because of his belief in Mormonism not in spite of it.
Romney has not governed in a contrary way to this belief.
Many people have been trying to make this point over the years, and to some extent have failed because unfortunately most people (even Mormons) know little of Mormonism and when it is exposed view it as a personal attack on individuals (which it is not).
He didn’t exactly establish a Mormon caliphate in Massachusetts when he was governor. It appears to be the same collection of tax-and-regulation-loving morons it’s always been.