Add tasks to task list using a workflow and send email 7 days before due date?

Question

I am a novice with SharePoint and would so greatly appreciate your guidance. We have SharePoint Online with SP Designer 2013. I have poured over the internet, but only find partial guidance. I need to

1. Assign tasks to employees to request submission of a monthly report. User does not want to manually enter tasks as there are many employees and assignment needs to occur each month. For example, they have 100 groups with a dozen employees in each group. Different managers oversee different groups. Manager A manages 20 groups. The goal is for the employee to get a link via email to take them to the form to enter Monthly Report which is saved to the Monthly Repot List. The employee will not be marking the task complete manually. See #3 below. (Note: I thought maybe I could use a Start a Process workflow, but have not made progress.)
2. Send the initial email reminder 7 days prior to the due date. Include a link to the Monthly Report List new page so they can be taken to a blank/new form to fill in the report (e.g., Employee Name, Report Month, Report Year, Accomplishments, Ongoing Tasks).
3. When the employee submits the form and it is added to the Monthly Report List, set the task for that employee to Completed. (Need some way to mark the employee's task in the Task List to completed when the item created in the Monthly Report List. We will not be asking the employee to go into the task and mark it complete. The purpose of the task list is for the managers to automate the emails and see who has / has not completed the task.)
4. If the task is not completed 2 days before the due date, send a reminder email.
5. If the task is not completed on the due date, send a reminder email.
6. If the task is not completed after the due date, send an email reminder until it is completed. This email has different content.

Some questions:

1. What type of workflow would one suggest for automating assigning tasks on a monthly basis?
2. I've seen videos and such about sending notification. Would they be a part of the logic of the workflow suggested in the prior question? Or is the best practice to create separate email notification workflows and have them always running?

Please let me know if you need any clarifications. Thank you!

Answer 1

SharePoint Online has a bit limited functionalities in terms of workflows so it's hard to say what would be best to solve your case. I'd always create e-mail notifications as a part of a workflow, that should be easier to maintain in the future. Anyway, if your long-term goal is to deliver more and more workflows, I'd consider a 3rd party platform to handle that instead of out-of-the-box functionalities. That should provide more features that would be easier to configure.