You can build a workflow that consists out of a combination of line items, a list, and a time dimension. By using Dynamic Cell Access (DCA) you can ensure that once the date field and a submission button is ticked you lock the input data. After approval/rejection you can keep the data locked or re-open it again. The email notification button in the NUX can be configured only in the NUX directly, you have to pre-specify the recipients per button.
Once Anaplan delivers the new additional workflow functionality you can assign tasks to specific roles/users. This would probably still need DCA on the back-ground so the effort that you're taking now isn't lost completely due to new update.
Kind regards, Stef Jansen in de Wal Finext Performance Management