Ask how they intend to pay for a year or two of rent.I ask for a statement of assets and discuss any red flags or ambiguities with them.

@Chris Blackburn, while I can't speak to this specifically, there are a few red flags I see in your post.1: A Realtor has to be a member of the national association of realtors, an industry trade group primarily focused on your typical home buyer.  

The fact that you've "put over 5 offers on houses since February" and moved to a different strategy is a huge red flag for me.

I purchased a mixed-use triplex with the bottom floor zoned commercial. 

Is this a red flag, or could it just mean there’s an untapped market here?

I have just received the same callThis a legitimate business model for a STR company, but the website raised a lot of red flags and I would not feel comfortable doing business with them.

I'm a licenced Broker and I also handle project management for flippers, contractors, etc.FEMA 50% Rule: ALL of the homes that exist in a Flood Zone have a 50% limit on work that can be done to repair them without bringing them into compliance with current flood standards.

I just bought all the drywall, cement board, and a 3/4 full thing of red guard water proofing that I need for my entire bathroom remodel for no joke $110, that would have cost me $400+ at the store but someone else who already finished their bathroom just had a ton left over.

Are there any red flags or challenges specific to this neighborhood that I should keep in mind?

My dad's mixed use property was grandfathered as it was built in 1890, before zoning laws went into effect here in the 1920's.