Under the Equal Credit Opportunity Act, every applicant can require a written explanation for why they were offered less favorable terms or denied.

So why would you deny somebody IF this were a rental, but not care about the negatives if it's a roommate.

I have found more mold underneath the counters and cabinets in the kitchen and she is denying it and I found proof that they painted over mold on the walls so they did know about it.

To tear off and replace, I am looking at 15k before replacement decking (had a few quotes from both established crews and side-job roofers).I also had a leak a few months ago after a hail storm that I tried to go through insurance, but the claim got denied because there was not enough damage to break my deductible. 

For my application process, I have a standard denial letter that I send to every applicant that has been fully processed, but denied.

We were first denied due to a cash offer but went under contract a week later.

You cannot deny them if they do even though this is usually fraudulent.

Is it permissible to deny a candidate because the other tenants get “creeper vibes” from him?

Can the tenant deny my access if I give them enough notice ( > 24 hours)?

If you have a claim due to anything happening in the MIL Suite your insurance carrier will likely deny the claim as you are using it as a rental.