There are the research resources of the LDS Library online and at Family History Centers of Books, microfilms, microfiche, indexes and factual records of genealogy databases at LDS Family Search website. On their website they add the family trees submitted by others in the search results. The LDS Website can not "make corrections" to those family trees, nor do they verify the tree is correct and has source documentation. So if you found a tree with incorrect information about a family member you look at the information of who submitted the tree and best you can do is contact the submitter about it (if the contact address is not outdated and still correct and access to it was allowed). But in reality it can not be corrected unless the LDS website has the ability to delete existing trees at the request of the original submitter and I would think a that person would not bother doing so, even if they could.
You mention "Pre-Strangite" records. Again reading early church history there were several times "LD settlements" were force-ably removed from areas and records and property were lost. You need to search for the records of each of the settlements in the counties and states they were established, prior to Joseph's Smith's death, to find your ancestors "Pre-Strangite". State Archives might have them or County Libraries. You must also remember there was the Civil War, and lots of court houses and records were destroyed during that time. Your best bet is state and county land, census, deeds, cemeteries, court, tax, death, marriage and birth records, not connected to the LDS church to find ancestors.