Do you expect LDS-standards in submissions that are not LDS-related (for example in a fantasy submission, would you expect the characters to live LDS-standards)?
I am an LDS publisher, so yes, I do. Obviously your antagonist would be exempt from moral behavior, but your protagonist should be someone the LDS reader would respect and respond to in a positive way.
If you intend to publish nationally, then no, I would not expect the characters to live LDS standards—but I would hope that your main character would still be moral and ethical.
(See more here.)