There are many ways to create this, personally I would make a entity with an ENUM connected to the Account with the user status.
Then when showing the form you can direct them to the different forms (different pages) or create one page with different questions based on this status.
Hope this helps
For the second part of your question: You should make quees that start automatically or scheduled events that start depending on time intervals. A microflow wil check the status of accounts periodically and generate tasks for accounts whose status are available according to your enumaration values.