Check out the E-Myth by Michael Gerber.

I always check to make sure that the "contract may not be reassigned" box is checked. 

Check with local banks and small credit unions in the area.

I'll add while not a big fan I checked into Zillow and they are suggesting a $90k annual spend for 5 possible leads per month in areas 1-2 hrs drive from my office and mostly buyers, that makes no sense for my current goals.

It's definitely worth checking out!

Check to see that your home owners or have your tenants get renters insurance. 

Think about how far under market your new rehabbed price would have to be to make it worth it for the tenant’s to move an extra time?

At that point, it's worth researching and finding a solution that better meets your needs. 

You can run background checks and credit reports on prospective applicants.

However to your point, using them for only a a few loans in a policy that wasn’t designed properly, wouldn’t be worth it.Most of the people who downplay it online, don’t explain the full picture unfortunately.