You can get these reports in you Constant Contact. For the unsubscribed, you can go to the Contacts Tab, then click on the unsubscribed link on the left. Then you can select all the unsubscribed and export the list to excel.
For the changes, you can go to the Segments link under Contacts and run a segment report that includes the date added and last date changed. If these two dates don't line up, then the contact has been updated.