I haven’t had the plumbing issue properly diagnosed by a professional. I have had the plumbing cleaned 2x in 3 months by a drain cleaning service. I have also spoken with the neighbors that have the same floor plan as I do and they have all told me about the same plumbing problem. They have had their plumbing properly inspected and it was determined to be a design flaw. I haven’t met anyone yet in the neighborhood that has signed on to having their home inspected in anticipation of a class action suit.
The other problems appear to be cosmetic for now. The home inspection did not reveal any obvious or visible code violations or damages.