This may not be exactly what you need, but this will give you a list of the Roles defined for a Product and the team members who are assigned to them. Maybe you can use this to figure out how to get exactly what you need.
I have also included a report that lists the Change Record task statuses. Hopefully it will give you some ideas on how to get the Task Sequence information you need.
btw.....These arefrom a v9.1 system.