The biggest thing you should look to get during DD period are: current lease (which you already have it seems), P&L statements for the past 2 years, any major repairs done (receipts), sub-metering (if applicable), what you owe as landlord vs. what tenant pays, estoppel agreement making sure you & tenants are on the same page,  etc.Best of luck!

However, I was really hoping what I had read all these years about it being easy to evict someone who is MTM in your primary would be true...The tenant is not a friend, just someone who is mentally ill and did not disclose that on their application.

I thought about going through my credit union, but I know that an application will hurt my already almost non-existent credit score. 

DO NOT re-list the property or start accepting applications until all the repairs are made and the tenant is completely moved out. 

Because I'm genuinely not sure if what you're saying is applicable to where I live.

There has also been a few items and snow tires stored since then belonging to the parent of unit 1. 

The mentality is "Ban the 46 OZ soda at the convenience store because people can't control themselves and they are too fat." 

Do not write "full gut job" on permit application.

Again, the BiggerPockets store has some books for this or you can learn by watching podcasts, reading blogs, and interacting on the forum.

Wanting 495 for application fee no return only credited to another project if they think is a fit