He also told me he changed the locks on the door so she couldn’t come back, and if I try to evict him he will drag it out and wreck the place.

The OP wants another thirty years max out of this sidewalk, and the house is probably going to go to the wrecking ball just a few years after that.

That doesn't mean it's always a train wreck; I've had tenants build nice brick patios and do other stuff like that, and hey great if it increases the property value or decreases your cost, but I would be real careful with that.

Having a death in the family can wreck havoc on the household finances especially if they didn't have proper health/life coverage.

I have had animals in a very nice house in Cleveland Hights nice area, wreck the place. **** happens everywhere. 

Well, the tenant buyer would wreck the place and move out in the middle of the night.

They have a problem and you have a solution and they will choose to let the process run its course and have their credit wrecked.

We haven't had much luck closing off market deals in the neighborhoods we're active in (Class A / B+ neighborhoods for the most part), and when you can get that kind of MLS action on absolutely wrecked properties I'm sure other investors are having as much trouble scoring deals off market as we are. 

Many tenants would just run it as is allowing it to slowly wreck your floors. 

A house in Hayward that's a wreck with acre lot and rehab and add a unit, hold long term?