I would personally not vote for someone who was Mormon, Scientologist, Muslim, Moonie, Krishna, etc.
It’s not bigotry, it’s my right as an American to vote my conscience.
Hell I’d take a satanist over Obama in 2012. At least he’d be honest about his faith and quite frankly things couldn’t get much worse.
I generally agree with what you said. I have voted for Mormons in the past but I don't think that I would vote for a committed one as POTUS or for a ticket with a committed Mormon as VP. I have seen first-hand the influence that the "church" has on its committed members and it could be too easily exploited by unelected men with a different agenda. A jack Mormon who lives a respectable life might be a different story.
The thinking of our candidates on spiritual matters provides good information to us about their character and thought processes. I think that it is perfectly okay for an individual to include this in the evaluation of a candidate.
I was dismayed by a graduate student in the 2008 election. When a comment was made about how many might not vote for Romney because of his Mormonism, the student responded with the statement: "That's unconstitutional", apparently unaware the religious test doesn't apply to the individual voter's decision process.