I am testing 2.1.0-rc.1
When you go to orders in admin would it be possible for each payment method to have its own "received" status.
Authorize: received - A
Paypal: received - P
Cash on Delivery: received - C
Creating different statuses can be done in admin but I wouldn't know where to implement them in the code. I suppose if you crated the receive status you would also have to do this for the others, pending, cancelled etc.
Just a thought as something is needed to see at a glance in admin where the payment came from.