I also found out that the contractor I hired to fix other issues found during the inspection and were part of the resolution were never completed but I provided the buyers with invoices that the work had been completed. 

Are all my invoices uploaded to my owner portal?

It takes:- 1 minute to enter a tenant from contact details, lease details, deposit and invoices. - less than 20 seconds to enter a check. 

Naturally he would have dealt with the deposit as he'd have to invoice the tenant for any repairs.

The city is in charge of invoicing homes just for this reason, even though a private may be supplying the services. 

 $.50 per transaction, you can send invoice automatically, they can pay automatically.  

Hemlane provides an actual service (assuming "Smart" plan is used) where they receive the request, work with the tenant to figure out what's going on and try some basic troubleshooting and then if needed call in the professionals and make sure everything is done to the tenant/owners satisfaction (pictures, invoices, etc.).

He really liked using the automatic paper folder I had and begged to do it, so I taught him to run my client invoices through the folder, put it in the envelope so the address was in the window and put the stamp on. 

The the actual utilities costs were lower, we provide the option of retaining the balance in the account (for future months where utility costs will be greater) or applying the balance towards their next month's rent.If the actual utilities costs were greater than they prepayment amount, we invoice the tenante for the balance {this has only happened once}.

I have sometimes seen owners give the prop mgr 10% ownership to have a little skin in the game but they are usually contractors that do a little more than just invoice and collect rents.