I'm missing so far single phpMyAdmin functionality, that is the one from database->operations: "Copy database to:"
I'm using this often before doing manual changes to create "backup" copy.
How about extending the "Alter database | Database schema" submenu to contain also "Copy to" which would lead to subpage with options:
name of copy:
only structure / structure+data
Not really sure about other pma options, I need valid full copy to serve as backup/recovery, so that's what I expect.