How much are novel submissions censored to fit LDS "standards"? Do most publishers censor similar to Church magazines or are they more open to situations outside traditional LDS values?
Depends on the publishing company. Some are very circumspect in the topics and treatments that they will consider for publication. Others, though few in number, are willing to take on non-traditional treatments. You can easily tell which is which by a quick browse of their website or reading a few of the books they've previously published.
Also, for most LDS publishers, it's not so much a case of censoring what doesn't fit LDS standards, as promoting and selecting items which do fit those standards. I know that's a small distinction to those attempting to sell manuscripts which explore things outside the LDS box, but it's a distinction that is important to me.