I dropped a huge inspection report on them, made them rethink relisting.

Do I need an inspection on my primary before renting it out?

How are you going to inspect the quality of work?

Sorry that you had a bad inspection and the sellers were not honest. 

Better tenant selection and regular inspections will stop this from happening.

Hi Elvis,You will need to fill out a construction permit if you are doing a major renovation, which requires an inspection from the city to ensure the code is followed.

They can also point you to what permits and inspections you will need to get to CO (Certificate of Occupancy).  

I asked for a thorough inspection report and months later I finally got it.

I would probably start monthly or bi-weekly "safety inspections" to A) document any lack of evidence of risks/issues to the tenant's safety to be prepared to legally defend yourself in the future, and B) to monitor for new/worsening damage to the unit.

The inspection report came back, and it's pretty bad.