Do you guys keep security deposit in a separate bank account and if so what kind?

Either publicly share here if it will help others or shoot me a PM. 

Egress doors must open directly into the public way or to a yard or exterior court that is open to the public way (IRC), similar in IBC.   

We'll see what zoning and public works has to say. 

Your only safeguard is the value of the property which is security for your investment.

Are there any security lights?

In either case there most likely would be a public record showing the transaction and parties involved. 

The development plan for that space will include a "Public Market" and new private commercial space, offices, and housing.

Or is this your way to tell the OP to check the free public records in the OP's selected county? 

a simple e transfer gets them paid and being that it is a second job for them, their fee should be fairly cheap.If you have about 20k in cash on your own, i would look to secure another investor or solicit friends and family.