If I mark as SPAM, don't offer Unsubscribe Option
If I go to mark an email as SPAM, I don't want to unsubscribe from it. I think you have misinterpreted what others have asked for when they want to unsubscribe from an email in their SPAM folder that they know is not SPAM.
I know this is SPAM, and honestly, I think unsubscribing from it will just inform the SPAMMER that mine is an active email address. Just move it to the SPAM folder and block it in the future!