I had a contractor in last week who looked at a few walls and told me they are not load bearing, no problem at all to knock them out and move them to change the floorplan slightly.   

I am not saying this to be a jerk but to encourage you to think about new ways to find leads; bandit signs (almost always illegal but very effective), door hangers, knocking on doors, buying a direct mail list.I hope that you are able to make this work.

I don't have the time or energy to knock on doors every month to attempt to collect rent, or worry about crime.

After the encouragement and advice from these awesome BP friends, I think we will pull a Brandon Turner and give them two offers--One with the price knocked down to make up for the repairs, and the other requiring the issues to be resolved before we close.

I thought about driving around and door knocking, or sending mail-outs to specific properties.

Door knock, cold call, and work your sphere.

Didnt think it would crap out so quickly Haven’t dealt with this in the past but should we knock $ off the rent?

Pay them for an hour to knock on the door and check for you.Good advice above about calling police or welfare as well, but I'd seriously consider making a trip and interviewing some PMs. 

Door knocking and purchased directly from home owner.

I don't disagree that you should at least start the eviction process, but I'd knock on the door and confront her, in a professional way, obviously.