If they're only willing to pay by check, it could be a red flag in my opinion. 

She would have money for Aug rent, if not red flags because what was she going to do if she stayed.Her leaving on the 20th means you have some time to go in and clean it up (probably not much to do as she was there for 4 months) and maybe get it rented by Aug 15.

There are facebook groups just for RAL Managers, so get in contact with some of the members and see if the person has any red flags.

I played baseball at the college I am trying to rent out so I spoke with the coaches and they will recommend players to live at this house.

But with all the red tape, why would you want to?

"High demand area" and "off market deal" are red flags for newbies!

Insurance red flags.  

This will give you insight into their financial health and stability.Look for any red flags, such as high debt levels or irregular financial practices.Understand Their Underwriting Process:Inquire about their underwriting criteria and process.

Five Pilllars realty was a key player for this project.

Testimonials are a huge red flag to me as they are difficult to verify and could be paid actors etc.