Jo - You Asked.
Maps of Dascen Elur - intriguing. Someday there should be.
Mages in Amroth - not currently. There is a reason.
Arithon's reputation with the sail hands outside of Karthan - his existence was known to them, and rumor could have lent a fearful edge to the gossip – sailors are about the most superstitious lot going. Not hard to imagine the stories would have been exaggerated. Given the s'Ffalenn reputation on the high seas, adding a son who could wield shadow would have been right terrifying, seen from the outside perspective.