The legal is pretty close to being done, but there are some Anti Can Spam Act issues to sort through.  

Paul, here in NJ the anti-eviction statute is such that you can't simply decline to renew a tenancy unless it's an owner-occupied 2-3 unit.

This is a different sort of  "hardening", but today in a unit I'm renovating I changed the ugly Segal vertical deadbolt to a standard cylindrical deadbolt, but with the addition of a steel plate "anti-kick-in" plate buried under the inside casing with 4" screws into the jamb.  

I just wanted to update this thread with what happened after I completed the purchase of the SFH.It turns out AZ passed something of an "anti-squatter" law a few years ago.  

Flood insurance rates are likly to go up and people are going to migrate out of the most exposed ares.I like your anti-cyclical thinking, but I would think twice about this "opportunity". 

Most members here are "anti-guru" but I started off with Fortune Builders years ago and it was a great start.

I grew up in a family who's anti-debt and try to avoid debt as much as possible.  

Income source is a protected class, it is listed on the site you linked.State and local laws often extend anti-discrimination protections to other categories, such as age, marital status, sexual orientation, or source of income.

That extra sauce in Bay Area is limited land and anti-growth activism.

If you're not in the anti-Durham crowd there are lots of options there.