That is, buy one home in city X (where I don't live), live in it a couple of months let it be an STR the rest of the time and then the next year (or in two years) repeat again in the same city. 

Create a list (you can download a csv from your phone) of ALL of your contacts.2.

Hey Chris, a few thoughts here.Considering that office is not attached to the house, I wouldn’t add any footage to the total home square footage; however, you could advertise that office space and amount of footage and amenities in your remarks.If you’re a Realtor or are using one for the sale, your local MLS may have fields dedicated to additional footage for other buildings on the property, such as ADU’s.The other point is that typically, perhaps depending upon location, a space needs to have heating to count in the square footage, which this office doesn’t have if I understand correctly.Consider contacting an appraiser to inquire about how they would handle this space on an appraisal, or a Realtor.

We are looking to capture a rental or two and one of those possibly being another STR. 

It allows tenants to increase their credit scores by an average of 60 points, and I provide it free of charge.I have over 600 adult tenants.

@Tinia JamesIf you receive a 1099 showing income from one of your deals, you have to file a Schedule C to report that income.

@Robby Sanchez rules of thumb don't work, as others here have stated. 

Are there specific zoning or structural challenges in Florida I should be aware of?

We do monthly meetups in Northern NJ and the West Coast of FL, but have not pushed them into NY yet.

I would imagine it ended with him making no money as this sounds like the biggest steaming pile of poop I have ever heard of.