Once the municipal/state requirements are all set, do a thorough screening for any prospective tenants, have a solid lease ready to go, and take move-in pictures to have on record for any security deposit deductions after they move out.

They weren’t thrilled about moving, but we worked with them—returned their deposit and offered cash for keys to help them transition into a new rental.

For as much as attorney's charge, they should be able to answer this question.The deposit can be used for cleaning, repairs, and unpaid charges.

She co-owns other cash flowing rental with me that she paid her 20% deposit on.

From my point of view for event guest screening and security deposits, Superhog is reliable and integrates well for STRs and events, but you might need to adjust its setup for your use case.

Cash to invest (enough for deposits, skin in the game lenders want you to have, closing costs, carrying costs, and to kick off rehab work).2.) 

It was supposed to be only  1 and once we dropped back to 1 we could instantly see the difference.

My friend recently told me of this scenario where the person I lease to would perhaps then double book individuals and keep deposits. 

Given your questioning, it sounds like you might have put a deposit way too quickly on that property.

He has paid rent weekly via auto-deposit into my account for 24 months.