Notify the police that you have a person who is threatening other residents and that you have issued a Trespass Warning to him.And, know this:  you have knowledge that a dangerous person is residing in/on your property. 

Seems dangerous to me. 

And, if this property has flooded twice already you can be in danger of not being able to get permits from the city.

Consult an attorney and get out of this dangerous situation.

If you're fixing this to keep as a rental, I would only care about the things that were stopping me from making it a rental now, or could be so tremendously expensive or dangerous later that I would want to take steps to mitigate it now.

If it says you should leverage your RE, then use it to buy more, if it says you should de-leverage your RE, then put it there.Having said all that, it's clear you are uncomfortable with the risk you have, so the my advice without knowing anything about your IPS (very dangerous, for you) is to pay off debt.

In the area I invest in the City has to demo several properties a year because the owners can not keep them up and they become dangerous. 

The only bully in this is you, slandering me for informing you of your dangerous and ignorant advise, you told someone to do something illegal and obviously had 0 knowledge to speak from.

It is crucial to make the distinction between your taxable estate and your net worth.

Lead paint itself is not dangerous - it's the lead paint that is deteriorating—peeling, chipping, chalking, cracking, etc, that is problematic and requiring remedy.