-How should I handle security deposits and rents?

He is on fixed income (social security + private pension) and we inherited him when we bought the property.

Cable, internet, home automation, security.. 

He explained that they have money from savings and can make a security deposit.

You will need a good business formation/securities attorney. 

I only rent now to people in essential Industries or with guaranteed payments such as disability or Social Security.

Medium term renting out of the 1/1 apartment at 1200/monthLong term renting out the 2/1 at 1900/monthPITI = $2455 Additional predicted monthly expenses and predicted vacancy: $310/monthCash flow per month = $335Cash Down: $8700Investment to furnish garage apartment for medium term renting: $4500Cash on cash ROI = 30.5%Renters secured on both the day after closing to move in on 4/1.What made you interested in investing in this type of deal?

In her case, since she just came out of bankruptcy, she was unable to secure a loan modification...not sure if from the bankruptcy or because she'd already modified it once.

Even if you just spend a few extra months trying to secure financing, the interest could really be a bummer.  

Occupied- As a lender we like to see long term leases in place with a security deposit, first and last of course and length of leases.