I don't know the cost of your fridge, but my CPA would simply expense it.The funny story is a rehabbed a house, bought appliances in a refrigerator, hot water tank and depreciated the entire rehab over 27.5 years.  

It's understandable why many investors and/or accidental landlords would opt to simply self-manage.

There is simply way to many things that can go wrong building a new home with zero experience.

I am currently in learning mode and am looking to actually enter the real estate space in a couple years or so. 

You simply have no credibility otherwise :) 

It violated HOA rules for you to rent to a sex offender so the lease should not have been entered into in the first place.  

Since you do not have that option - at minimum get a photo I.D. to know who is entering your home. 2.

That said, it could be that the location of your property has some sort of local ordinance that has a 90-day limit, and Airbnb is simply following that.

Does anyone know if the fire sprinkler system will be needed if I simply rezone the basement as part of the first unit?

Enter a maintenance request, assign a vendor, and attach a fake invoice.