>>35772124The ingame map is also good at telling us what's missing, it seems like all the towns are there and bar the western routes connecting the islands they're all there too, it even tells us where some of the dungeons would be. There's enough here for someone to flesh out the internal dungeon maps. Even then, caves in towns aren't considered, and then you have stuff like the forest west of old Canalave and potentially another one in the wasteland north of it going off this map.
>>35772460I think they're bridges, which would have been based of the likes of the Honshu Shikoku bridges or the Kanmon Bridge, or even the tunnel.