First off, the biggest issue was I had been planning to do most of it myself. 

Multiple ADUs on any is not allowed, but I have only heard of it being an issue in SF zoned areas or if unit count hits 5.If you want to be sure of getting non-commercial F/F follow the rules. 

The issues can be local so look for someone in your area who is posting and try to contact.   

UPDATE:  After 4 days of back and forth with Airbnb CS, they finally decided to do the right thing and issue my payout for a reservation that a guest cancelled in the amount of $1,333.75. 

It provides an opportunity to see what's happening in the units.You still have the ability to evict for lease violations, but your less likely to face non-payment issues. 

I found this deal through a wholesaler in my network and I negotiated with the wholesaler to get a lower price with the buyer because of an issue with an attached empty lot.

@Josh Ball mentions, there are issues with foreign investors but, nowadays, it's not necessarily on the tax front anymore.

Most landlords don’t go looking for a property manager until they’re dealing with an issue—tenant headaches, late rent, maintenance problems—so your marketing should focus on providing solutions, not just listing your services.Marketing Strategy: Combined or Separate?

Live way below your means and save the majority of your income.

They say not to make two major life changes within a year.