I have always used Zillow/Redfin to find property and then use other tools to verify and evaluate details about them (like finding out how much rent you can get,  confirming property taxes on the county website, HOA fees, etc.). 

I do AirDNA first and then look for confirmation or rejection on Airbnb/VRBO. 

I was contacted by Mike Grimes, whom confirmed they are a broker. 

My RTR strategist confirmed multiple times their very high degree of confidence in the RTR monthly rent projection, sub 30-day vacancy rate, and PM team performance.

Would confirm to the rest of the sfr in the neighborhood?

My thought process is that you are ultimately responsible for all the numbers being vetted to you.You are doing a good job confirming all the numbers.Everyone else wants you to close as fast as possible becuase they likely get a bonus / commission for closing.Best of luck to you!

I agree, you need to confirm this with the city.

I would confirm the home warranty they're referencing and it's coverage verses what their maintenance team will be doing.

Your Property Management Agreement should also confirm if there is penalty for canceling. 

If you hear from him again or an attorney, be sure to respond immediately by your own attorney if necessary.Not sure what the laws are in your state, but you want to do whatever you need to to confirm the tenancy has ended (whether that is by abandonment on his part or with proper notification to end a month to month)