Roaches should be fine Jace. I've read many many articles and scientif research papers on roaches and not one of them said that any of their colonies suffered from inbreeding except for one which wasn't too bad. She said after years and years of having a colony this scientist noticed a reduction in the number offspring produced by individual females.
They were dubia and wild caught. When first acquired, the females regularly had between 40-50 offspring each time. After years the litter size was averaging 30. She imported more wild dubia and the numbers went back up. Inbreeding isn't really a problem in many "less advanced" organisms. Some scientist believe inbreeding is better for a population to rid the gene pool of inferior genes.I would get into it more but I've already typed quite a bit there.