1.Set automated close to  72hrs when marked resolved

2.  Turn off incident reopened if end user replies

check- Alert Notify Technician by email when there is a new reply from requester

If incident marked resolved status will the tech still get the notification?

Can a business rule be created if body contains " Thank you" close ticket on resolved incidents?

 This would mean it would auto close in 72hrs, allow the end user to  close themselves, a reply would just be sent to the technician and they can decide if it needs to be reopened and if a user replies just thank you automatically close tickets based on a business rule