They aren't all civil parishes. Civil parishes were introduced in 1845 so any that pre-date that are ecclesiastical parishes (presumably Church of Scotland)

Yeah, it's just a placeholder for time period and has never had boundaries. There's a note tag saying as much. Originally it spanned 1201-1797 but as I have worked back from 1797 and added more iterations I have pushed back the end date. Eventually it should either be deleted or represent a specific narrower time-span. At the moment it is as much for the chronology as anything, but also gives somewhere to keep "notes" (mark down dates of changes not yet implemented) and to hold the imperial circle/Bohemian crown relations. 1659-1678 (https://www.openhistoricalmap.org/relation/2830620) is also currently boundary-less due to complications with the Spanish Netherlands.