I think her points are valid to a degree. There are major issues with Romney being a Mormon. This particular issue is probably overblown though.
He probably wouldn't be more beholden to his church leadership than a Catholic candidate would be to the pope and that argument is old hat now and nobody is really seriously arguing that we shouldn't have Catholic candidates that I know of. So probably there's nothing to be too concerned about with the Mormon issue either.
I would vote against Romney on the fact that he was a Mormon except for the fact that the alternative, Obama, is even more unacceptable and follows an even more freakish version of religion.