Q U E S T I O N HUMAM INBREEDING?

It isn't at all certain there will be a problem. The problem is that negative recessive traits will be much more likely to be expressed. On a related subject, many environmentalists exaggerate the danger of a small population by saying they can't produce viable offspring without some arbitrary number of breading pairs. In fact a species that is evolved to have fewer numbers will also have greater section against negative recessive traits. A huge population would have very little selection pressure against recessive traits relative to an animal that had very low population. Bottom line is that is unwise but might not be harmful.