Did you collect a pet deposit?

Renter's Insurance is a cheap date for the tenant; it protects their security deposit and assets. 

Large deposits are nice, but very difficult to actually get access to escrow funds in the event of default.

Each jurisdiction is different, but typically include a substantial deposit due same day up to full price deposited that day. 

I don't think you are going to be able to get insurance for two separate living units in a single-family when they are both illegal and likely do not have the correct egress windows (basement) for fire safety which could subject you to huge liability if something happens to either party.

And all the folks that could never get a deal to close and lost their deposit to them and EM etc etc..

-Structural (foundation, wall, ceiling and floor)-Roof and Exterior(Roof Condition,Gutters and Downspouts, Siding, Windows and Doors)-Plumbing (Water Pressure,Leaks, Drainage, Pipes)-Electrical (Wiring,Outlets and Switches,Breaker Panel, Lighting Fixtures)-HVAC(Air Ducts, heating and cooling)-Water and Moisture Issues(Attic, Mold and Mildew)-Kitchen and Appliances-Bathrooms-Pest and Insect Problems-Safety Features

Instant equity creates a margin of safety.

I don't rent furnished and others may be able to point out where this is flawed, but I would consider renting the furniture SEPARATE of the unit because that may allow you to collect a deposit on the furniture.

Think of all the things that could go wrong and see if the lease addresses them: unauthorized pets or tenants, early termination, security deposit, lease violations, late rent, eviction, lawn maintenance, parking, etc.5.