However, the landlord, who isn’t identified by name in the ruling, should have denied the dog request because Cohen lived there first and the dog posed a direct threat to her health.The court concluded that Cohen, who suffered allergic attacks, was entitled to her claims of breach of lease and breach of the “covenant of quiet enjoyment.”The ruling shows Cohen has a “medically documented severe allergy” to pet dander that causes nasal congestion, swollen sinuses and excess coughing.

Overall, are the rankings useful in identifying a market and does the methodology make sense for a real estate investor? 

You'll need to do you homework here and identify what's important to youAny checklist we have to keep: not sure what you mean here...

I started by using realtor.com to identify some properties of interest, and then contacted the LISTING AGENT. 

Hello fellow investors,
Sharing a Web map (MapLink) I have created to show the investment suitability by Zipcode based on a few metrics below.
To use this map, select the metrics (one or more) you prefer in the ‘La...

You have to learn how to identify a property in a market that will payoff later.

Instead of just patching another 1ft section of plumbing i had GC come out and identify the cause of the problem/cause of loss and initiated an insurance claim. 

Once I've identified homes in my price range (sometimes foreclosure.com will list the balance on the mortgage and that gives me a starting point), I drive by the home to just get a cursory view of the home to see if it's in good shape on the outside, check out the neighborhood and neighbors, and to see if the home is still occupied.

However, a 1031 exchange involves reinvesting the proceeds in the new property that you've identified for the "like-kind exchange". 

Right now I have about ~$80k + $40k (in my IRA that I may deploy) to start buying more homes in Kansas City, but would like to identify interest only lenders so I can cash flow the properties from day 1.