But neighborhoods can change quite quickly from one block to the next, and these aren't quite close enough for me to feel confident that they're truly comparable.One thing that jumped out at me while I was looking at the above county records is that it's officially recorded as a 2-bedroom, 1-bathroom, NOT a 3-bedroom, 2-bathroom (like the Realtor.com listing says it is). 

Tenants like this are already skittish during a sale, and getting them to sign another official document can be problematic, especially if English isn't their first language. 

Otherwise, I probably won't be able to get enough rent money to cover my expenses or even come close (I expect expenses like mortgage, PITI, etc. to be at least $2100 / month on a $300K house, but I'm a beginner so I may be wrong).Apparently it can also take a year or more to get your house officially zoned as a duplex and can cost a lot of money in paperwork and attorney fees to get it done.

Eveyone is making a big deal about this, and Ive been intimately involved in the lobbying of the law.....but if a landlord cant afford $100 for a window a/c unit, then they shouldn't own a rental property.

A reminder, when we military have occupied a primary for 2 years of of 10 years, we can exclude capital gains on the sale of that house: If you or your spouse are on qualified official extended duty in the Uniformed Services, the Foreign Service or the intelligence community, you may elect to suspend the five-year test period for up to 10 years.

You can print this one on your computer, no need for the “official” printed forms.W-9 asks them to enter their name, address, and tax ID – which can be a SSN, ITIN (for people who are not permanent residents) or EIN (business tax ID).

Do they remain to be tenants until they are officially given notice to vacate?

OR do I have to wait until the properties titles are officially in our names 2020 and then starting 2020 taxes I can start taking advantage of tax write offs.

I am just wondering from a contractual side what kind of paperwork would I need to make the lease official?

I would also speak to the local building official who reviewed and signed off on the repair.