I'm going to have to crunch a lot of numbers for the loan, property tax, maintenance (which should hopefully be low on new builds), and I have to figure out how to obtain an insurance policy for the units. 

Same goes for number of LLCs and what to fund them with, since bear in mind that CA tends to be more cumbersome and expensive to have LLCs than other states.California is generally more cumbersome than other states when it comes to taxes and filings.

We were even able to save the borrower from paying the hefty NYS and NYC recording tax by arranging for a CEMA with the existing note.

The house is a 3b/2ba 1,895 sq ft home but an additional sunroom built in which brings sq ft up to 2,055 (based off tax records my agent found).

Not sure what new tax laws bring to the table.

They didn’t go as strict as they threatened, at least not yet…https://www.atlantaga.gov/government/departments/city-planni...2 properties maximum and the first one must be  your primary home… so be prepared to move there and pay state income taxes  https://www.atlantaga.gov/home/showpublisheddocument/54610/6...you and your landlord will have to get this form notarized.Please just make sure you have a plan to keep making rent payments after your short term rental plans are banned.  

There was a property at the auction that sold at market, however it had a federal tax lien of over 100k attached to it.

I am in the process of filing taxes.

As I understand Federal Tax Lien will fall of after 90 days or IRS could redeem the property.

At today's rates I'm not sure it would cashflow by the time you add taxes, insurance, r&m reserves, etc.The average rate today on a 30-Year fixed is 7.38%.