File Submissions

I would say this is achievable just by creating a new Workflow Profile, using the Workflow Name "Process, Confirm, Certify" (or any other name that includes Confirm), using Confirmation Rules that check for the existence of such documents - Process and Certify steps will be left effectively blank, doing nothing (you might have to create a dummy Calculation Definition, set to "No Calculate", for any entity, so that the Process step will run).

You can then use all the usual security features of OS to restrict upload. The easiest approach would probably be Cube Views pointing to the intersections where such documents must be uploaded, and then leveraging the native menus on right-click. You can attach them to the profile with the Cube View Profile Name and they will appear on the Process tab. A more elegant (but burdensome) approach would be to design custom Dashboards to do the work.

As for automated notifications, you can have them fired from an Event Handler on the Process step.

I'm sure your consulting partner would be happy to build one of such solutions fairly quickly, they are pretty common requirements. If not, just get in touch to our Services team via your Customer Success Manager or Support.