Yes you can do this.
But you need to allow send from multiple list option in customer group.
After the list is created, edit it, and make it so that when somebody unsubscribes from this list, to be unsubscribed from the merged lists as well(you have those checkboxes there to help you with this).How do i make it so that once the merge lists is created, it unsubscribes from the other lists that was used to merge into this one list?
Nope.If I add emails to the other lists that were used to merge into this one list, does it add the new ones to the already merged list?
CorrectIf I delete the merged list that means nobody will be able to unsubscribe from that merged list correct?