What a good app to keep track of leases with tenants and collected rent money each month and automatically apply late fees if they don't pay on time?  

Lease apartments for people.

And I noticed that many of the unfurnished units were offered with a month to month lease... the kids would get cheap furniture that they didn't care about tearing up and giving away when they were done.

Ideally he will be stay there for 10 months and lease the property from the new owner while he gets ready for his move. 

You need to hire a Commercial agent to lease that for you.

If your HOA is ok with leases less than a year in length, you may have a potential medium-term rental given the proximity to Kennesaw State University and to Wellstar Kennestone Hospital.

Do you have any clauses in the lease about cleanliness that they are breaking? 

Leasing agent, maintenance guy, property manager, city hall-economic development, building permits. 

Good post with some items, most notably insurance that's generally just glossed over during underwriting.

However, one of them said they won't move in for 5 months but will sign the lease now, even though they're still renting another place during that time.